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基础c语言设计

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C语言设计谭浩强第三版的课后习题答案
1．5请参照本章例题，编写一个C程序，输出以下信息：
main()
{
printf("    ************    \n");
printf("\n");
printf("    Very Good!  \n");
printf("\n");
printf("    ************\n");
}
1.6编写一个程序，输入a b c三个值，输出其中最大者。
解：main()
{int a,b,c,max;
printf("请输入三个数a,b,c:\n");
scanf("%d,%d,%d",&a,&b,&c);
max=a;
if(maxmax=b;
if(maxmax=c;
printf("最大数为：%d",max);
}
第三章
3.3 请将下面各数用八进制数和十六进制数表示：
（1）10  （2）32  （3）75  （4）-617
（5）-111 （6）2483 （7）-28654 （8）21003
解：十八十六
（10）=（12）=（a)
(32)=(40)=20
(75)=(113)=4b
(-617)=(176627)=fd97
   -111=177621=ff91
   2483=4663=963
   -28654=110022=9012
   21003=51013=520b
3.5字符常量与字符串常量有什么区别？
解：字符常量是一个字符，用单引号括起来。字符串常量是由0个或若干个字符
而成，用双引号把它们括起来，存储时自动在字符串最后加一个结束符号'\0'.
3.6写出以下程序的运行结果:
#include
void main()
{
char c1='a',c2='b',c3='c',c4='\101',c5='\116';
printf("a%c b%c\tc%c\tabc\n",c1,c2,c3);
printf("\t\b%c %c\n",c4,c5);
解:程序的运行结果为:
aabb  cc abc
A N
3.7将"China"译成密码.密码规律:用原来的字母后面第4个字母代替原来的字母,
例如,字母"A"后面第4个字母是"E",用"E"代替"A".因此,"China"应译为"Glmre".
请编一程序,用赋初值的议程使c1,c2,c3,c4,c5分别变成'G','1','m','r','e',并
输出.
main()
{char c1="C",c2="h",c3="i",c4='n',c5='a';
c1+=4;
c2+=4;
c3+=4;
c4+=4;
c5+=4;
printf("密码是%c%c%c%c%c\n",c1,c2,c3,c4,c5);
}
3.8例3.6能否改成如下:
#include
void main()
{
int c1,c2;(原为 char c1,c2)
c1=97;
c2=98;
printf("%c%c\n",c1,c2);
printf("%d%d\n",c1,c2);
}
解:可以.因为在可输出的字符范围内,用整型和字符型作用相同.
3.9求下面算术表达式的值.
(1)x+a%3*(int)(x+y)%2/4=2.5(x=2.5,a=7,y=4.7)
(2)(float)(a+b)/2+(int)x%(int)y=3.5(设a=2,b=3,x=3.5,y=2.5)
3.10写出下面程序的运行结果:
#include
void main()
{
int i,j,m,n;
i=8;
j=10;
m=++i;
n=j++;
printf("%d,%d,%d,%d\n",i,j,m,n);
}
解:结果: 9,11,9,10
第4章
4.4.a=3,b=4,c=5,x=1.2,y=2.4,z=-3.6,u=51274,n=128765,c1='a',c2='b'.想得
到以下的输出格式和结果,请写出程序要求输出的结果如下:
a= 3  b= 4  c= 5
x=1.200000,y=2.400000,z=-3.600000
x+y= 3.60  y+z=-1.20  z+x=-2.40
u= 51274  n= 128765
c1='a' or 97(ASCII)
c2='B' or 98(ASCII)
解:
main()
{
int a,b,c;
long int u,n;
float x,y,z;
char c1,c2;
a=3;b=4;c=5;
x=1.2;y=2.4;z=-3.6;
u=51274;n=128765;
c1='a';c2='b';
printf("\n");
printf("a=%2d b=%2d c=%2d\n",a,b,c);
printf("x=%8.6f,y=%8.6f,z=%9.6f\n",x,y,z);
printf("x+y=%5.2f  y=z=%5.2f  z+x=%5.2f\n",x+y,y+z,z+x);
printf("u=%6ld  n=%9ld\n",u,n);
printf("c1='%c' or %d(ASCII)\n",c1,c2);
printf("c2='%c' or %d(ASCII)\n",c2,c2);
}
4.5请写出下面程序的输出结果.
结果:
57
  5  7
67.856400,-789.123962
67.856400 ,-789.123962
67.86,-789.12,67.856400,-789.123962,67.856400,-789.123962
6.785640e+001,-7.89e+002
A,65,101,41
1234567,4553207,d687
65535,17777,ffff,-1
COMPUTER,  COM
4.6用下面的scanf函数输入数据,使a=3,b=7,x=8.5,y=71.82,c1='A',c2='a',
问在键盘上如何输入?
main()
{
int a,b;
float x,y;
char c1,c2;
scanf("a=%d b=%d,&a,&b);
scanf(" x=%f y=%e",&x,&y);
scanf(" c1=%c c2=%c",&c1,&c2);
}
解:可按如下方式在键盘上输入:
a=3 b=7
x=8.5 y=71.82
c1=A c2=a
说明:在边疆使用一个或多个scnaf函数时,第一个输入行末尾输入的"回车"被第二
个scanf函数吸收,因此在第二\三个scanf函数的双引号后设一个空格以抵消上行
入的"回车".如果没有这个空格,按上面输入数据会出错,读者目前对此只留有一
初步概念即可,以后再进一步深入理解.
4.7用下面的scanf函数输入数据使a=10,b=20,c1='A',c2='a',x=1.5,y=-
3.75,z=57.8,请问
在键盘上如何输入数据？
scanf("%5d%5d%c%c%f%f%*f %f",&a,&b,&c1,&c2,&y,&z);
解：
main()
{
int a,b;
float x,y,z;
char c1,c2;
scanf("%5d%5d%c%c%f%f",&a,&b,&c1,&c2,&x,&y,&z);
}
运行时输入：
10 20Aa1.5 -3.75 +1.5,67.8
注解：按%5d格式的要求输入a与b时，要先键入三个空格，而后再打入10与20。%*f
是用来禁止赋值的。在输入时，对应于%*f的地方，随意打入了一个数1.5，该值不
会赋给任何变量。
4.8设圆半径r=1.5,圆柱高h=3,求圆周长,圆面积,圆球表面积,圆球体积,圆柱体积,
用scanf输入数据,输出计算结果,输出时要求有文字说明,取小数点后两位数字.请编
程.
解:main()
{
float pi,h,r,l,s,sq,vq,vz;
pi=3.1415926;
printf("请输入圆半径r圆柱高h:\n");
scanf("%f,%f",&r,&h);
l=2*pi*r;
s=r*r*pi;
sq=4*pi*r*r;
vq=4.0/3.0*pi*r*r*r;
vz=pi*r*r*h;
printf("圆周长为:    =%6.2f\n",l);
printf("圆面积为:    =%6.2f\n",s);
printf("圆球表面积为:  =%6.2f\n",sq);
printf("圆球体积为: =%6.2f\n",vz);
}
4.9输入一个华氏温度,要求输出摄氏温度,公式为C=5/9(F-32),输出要有文字说明,
取两位小数.
解: main()
{
float c,f;
printf("请输入一个华氏温度:\n");
scanf("%f",&f);
c=(5.0/9.0)*(f-32);
printf("摄氏温度为:%5.2f\n",c);
}
第五章逻辑运算和判断选取结构
5.4有三个整数a,b,c,由键盘输入,输出其中最大的数.
main()
{
int a,b,c;
printf("请输入三个数:");
scanf("%d,%d,%d",&a,&b,&c);
if(a  if(b    printf("max=%d\n",c);
  else
   printf("max=%d\n",b);
else if(a    printf("max=%d\n",c);
else
   printf("max-%d\n",a);
}
方法2:使用条件表达式.
main()
{int a,b,c,termp,max;
printf("    请输入    A,B,C: ");
scanf("%d,%d,%d",&a,&b,&c);
printf("A=%d,B=%d,C=%d\n",a,b,c);
temp=(a>b)?a:b;
max=(temp>c)? temp:c;
printf(" A,B,C中最大数是%d,",max);
}
5.5 main()
{int x,y;
printf("输入x:");
scanf("%d",&x);
if(x<1)
{y=x;
printf("X-%d,Y=X=%d  \n",x,y);
}
else if(x<10)
{y=2*x-1;
printf("  X=%d,  Y=2*X-1=%d\n",x,y);
}
else
{y=3*x-11;
printf("X=5d, Y=3*x-11=%d  \n",x,y);
}
}
（习题5-6:）自己写的已经运行成功!不同的人有不同的算法,这些答案仅供参考!
void main()
{
float s,i;
char a;
scanf("%f",&s);
while(s>100||s<0)
{
printf("输入错误!error!");
scanf("%f",&s);
}
i=s/10;
switch((int)i)
{
case 10:
case 9: a='A';break;
case 8: a='B';break;
case 7: a='C';break;
case 6: a='D';break;
case 5:
case 4:
case 2:
case 1:
case 0: a='E';
}
printf("%c",a);
}
5.7给一个不多于5位的正整数，要求：1.求它是几位数2.分别打印出每一位数字3.
按逆序打印出各位数字.例如原数为321,应输出123.
main()
{
long int num;
int indiv,ten,hundred,housand,tenthousand,place;
printf("请输入一个整数(0-99999):");
scanf("%ld",&num);
if(num>9999)
place=5;
else if(num>999)
place=4;
else if(num>99)
place=3;
else if(num>9)
place=2;
else place=1;
printf("place=%d\n",place);
printf("每位数字为:");
ten_thousand=num/10000;
thousand=(num-tenthousand*10000)/1000;
hundred=(num-tenthousand*10000-thousand*1000)/100;
ten=(num-tenthousand*10000-thousand*1000-hundred*100)/10;
indiv=num-tenthousand*10000-thousand*1000-hundred*100-ten*10;
switch(place)
{case 5:printf("%d,%d,%d,%d,%d",tenthousand,thousand,hundred,ten,indiv);
printf("\n反序数字为:");
printf("%d%d%d%d%d\n",indiv,ten,hundred,thousand,tenthousand);
break;
case 4:printf("%d,%d,%d,%d",thousand,hundred,ten,indiv);
printf("\n反序数字为:");
printf("%d%d%d%d\n",indiv,ten,hundred,thousand);
break;
case 3:printf("%d,%d,%d\n",hundred,ten,indiv);
printf("\n反序数字为:");
printf("%d%d%d\n",indiv,ten,hundred);
case 2:printf("%d,%d\n",ten,indiv);
printf("\n反序数字为:");
printf("%d%d\n",indiv,ten);
case 1:printf("%d\n",indiv);
printf("\n反序数字为:");
printf("%d\n",indiv);
}
}
5.8
1.if语句
main()
{long i;
float bonus,bon1,bon2,bon4,bon6,bon10;
bon1=100000*0.1;
bon2=bon1+100000*0.075;
bon4=bon2+200000*0.05;
bon6=bon4+200000*0.03;
bon10=bon6+400000*0.015;
scanf("%ld",&i);
if(i<=1e5)bonus=i*0.1;
else if(i<=2e5)bonus=bon1+(i-100000)*0.075;
else if(i<=4e5)bonus=bon2+(i-200000)*0.05;
else if(i<=6e5)bonus=bon4+(i-400000)*0.03;
else if(i<=1e6)bonus=bon6+(i-600000)*0.015;
else bonus=bon10+(i-1000000)*0.01;
printf("bonus=%10.2f",bonus);
}
用switch语句编程序
main()
{long i;
float bonus,bon1,bon2,bon4,bon6,bon10;
int branch;
bon1=100000*0.1;
bon2=bon1+100000*0.075;
bon4=bon2+200000*0.05;
bon6=bon4+200000*0.03;
bon10=bon6+400000*0.015;
scanf("%ld",&i);
branch=i/100000;
if(branch>10)branch=10;
switch(branch)
{case 0:bonus=i*0.1;break;
  case 1:bonus=bon1+(i-100000)*0.075;break;
  case 2:
  case 3:bonus=bon2+(i-200000)*0.05;break;
  case 4:
  case 5:bonus=bon4+(i-400000)*0.03;break;
  case 6:
  case 7
  case 8:
  case 9:bonus=bon6+(i-600000)*0.015;break;
  case 10:bonus=bon10+(i-1000000)*0.01;
  }
printf("bonus=%10.2f",bonus);
}
5.9 输入四个整数,按大小顺序输出.
main()
  {int t,a,b,c,d;
  printf("请输入四个数:");
  scanf("%d,%d,%d,%d",&a,&b,&c,&d);
  printf("\n\n a=%d,b=%d,c=%d,d=%d \n",a,b,c,d);
  if(a>b)
{t=a;a=b;b=t;}
  if(a>c)
{t=a;a=c;c=t;}
  if(a>d)
{t=a;a=d;d=t;}
  if(b>c)
{t=b;b=c;c=t;}
  if(b>d)
{t=b;b=d;d=t;}
  if(c>d)
{t=c;c=d;d=t;}
printf("\n 排序结果如下: \n");
printf(" %d  %d  %d  %d \n",a,b,c,d);
}
5.10塔
main()
{
int h=10;
float x,y,x0=2,y0=2,d1,d2,d3,d4;
printf("请输入一个点(x,y):");
scanf("%f,%f",&x,&y);
d1=(x-x0)*(x-x0)+(y-y0)(y-y0);
d2=(x-x0)*(x-x0)+(y+y0)(y+y0);
d3=(x+x0)*(x+x0)+(y-y0)*(y-y0);
d4=(x+x0)*(x+x0)+(y+y0)*(y+y0);
if(d1>1 && d2>1 && d3>1 && d4>1)
h=0;
printf("该点高度为%d",h);
}
第六章循环语句
6.1输入两个正数,求最大公约数最小公倍数.
main()
{
int a,b,num1,num2,temp;
printf("请输入两个正整数:\n");
scanf("%d,%d",&num1,&num2);
if(num1{
temp=num1;
num1=num2;
num2=temp;
}
a=num1,b=num2;
while(b!=0)
  {
  temp=a%b;
  a=b;
  b=temp;
  }
printf("它们的最大公约数为:%d\n",a);
printf("它们的最小公倍数为:%d\n",num1*num2/2);
}
6.2输入一行字符,分别统计出其中英文字母,空格,数字和其它字符的个数.
解:
#include <    >
main()
{
char c;
int letters=0,space=0,degit=0,other=0;
printf("请输入一行字符:\n");
scanf("%c",&c);
while((c=getchar())!='\n')
{
if(c>='a'&&c<='z'||c>'A'&&c<='Z')
letters++;
else if(c==' ')
space++;
else if(c>='0'&&c<='9')
digit++;
else
other++;
}
printf("其中:字母数=%d 空格数=%d 数字数=%d 其它字符数=%
d\n",letters,space,
digit,other);
}
6.3求s(n)=a+aa+aaa+…+aa…a之值,其中工是一个数字.
解:
main()
{
int a,n,count=1,sn=0,tn=0;
printf("请输入a和n的值:\n");
scanf("%d,%d",&a,&n);
printf("a=%d n=%d \n",a,n);
while(count<=n)
{
tn=tn+a;
sn=sn+tn;
a=a*10;
++count;
}
printf("a+aa+aaa+…=%d\n",sn);
}
6.4 求1+2!+3!+4!+…+20!.
main()
{
float n,s=0,t=1;
for(n=1;n<=20;n++)
{
t=t*n;
s=s+t;
}
printf("1!+2!+…+20!=%e\n",s);
}
6.5 main()
{
int N1=100,N2=50,N3=10;
float k;
float s1=0,s2=0,s3=0;
for(k=1;k<=N1;k++)
{
s1=s1+k;
}
for(k=1;k<=N2;k++)
{
s2=s2+k*k;
}
for(k=1;k<=N3;k++)
{
s3=s3+1/k;
}
printf("总和=%8.2f\n",s1+s2+s3);
}
6.6水仙开花
main()
{
int i,j,k,n;
printf(" '水仙花'数是:");
for(n=100;n<1000;n++)
{
i=n/100;
j=n/10-i*10;
k=n%10;
if(i*100+j*10+k==i*i*i+j*j*j+k*k*k)
{
printf("%d",n);
}
}
printf("\n");
}
6.7完数
main()
#include M 1000
main()
{
int k0,k1,k2,k3,k4,k5,k6,k7,k8,k9;
int i,j,n,s;
for(j=2;j<=M;j++)
{
n=0;
s=j;
for(i=1;i {
if((j%i)==0)
  {
if((j%i)==0)
   {
   n++;
   s=s-i;
   switch(n)
   {
   case 1:
k0=i;
break;
case 2:
k1=i;
break;
case 3:
k2=i;
break;
case 4:
k3=i;
break;
case 5:
k4=i;
break;
case 6:
k5=i;
break;
case 7:
k6=i;
break;
case 8:
k7=i;
break;
case 9:
k8=i;
break;
case 10:
k9=i;
break;
}
   }
}
if(s==0)
{
printf("%d是一个‘完数’，它的因子是",j);
if(n>1)
  printf("%d,%d",k0,k1);
if(n>2)
  printf(",%d",k2);
if(n>3)
  printf(",%d",k3);
if(n>4)
  printf(",%d",k4);
if(n>5)
  printf(",%d",k5);
if(n>6)
  printf(",%d",k6);
if(n>7)
  printf(",%d",k7);
if(n>8)
  printf(",%d",k8);
if(n>9)
  printf(",%d",k9);
printf("\n");
  }
}
方法二:此题用数组方法更为简单.
main()
{
static int k[10];
int i,j,n,s;
for(j=2;j<=1000;j++)
{
n=-1;
s=j;
for(i=1;i{
if((j%i)==0)
{
n++;
s=s-i;
k[n]=i;
}
  }
if(s==0)
{
printf("%d是一个完数,它的因子是:",j);
for(i=0;iprintf("%d,",k[i]);
printf("%d\n",k[n]);
}
}
6.8 有一个分数序列:2/1,3/2,5/3,8/5……求出这个数列的前20项之和.
解: main()
{
int n,t,number=20;
float a=2,b=1,s=0;
for(n=1;n<=number;n++)
{
s=s+a/b;
t=a,a=a+b,b=t;
}
printf("总和=%9.6f\n",s);
}
6.9球反弹问题
main()
{
float sn=100.0,hn=sn/2;
int n;
for(n=2;n<=10;n++)
{
sn=sn+2*hn;
hn=hn/2;
}
printf("第10次落地时共经过%f米 \n",sn);
printf("第10次反弹%f米.\n",hn);
}
6.10猴子吃桃
main()
{
int day,x1,x2;
day=9;
x2=1;
while(day>0)
{
x1=(x2+1)*2;
x2=x1;
day--;
}
printf("桃子总数=%d\n",x1);
}

6.12
#include"math.h"
main()
{float x,x0,f,f1;
x=1.5;
do
{x0=x;
f=((2*x0-4)*x0+3)*x0-6;
f1=(6*x0-8)*x0+3;
x=x0-f/f1;
}
while(fabs(x-x0)>=1e-5);
printf("x=%6.2f\n",x);
}

6.13
#include"math.h"
main()
{float x0,x1,x2,fx0,fx1,fx2;
do
{scanf("%f,%f",&x1,&x2);
fx1=x1*((2*x1-4)*x1+3)-6;
fx2=x2*((2*x2-4)*x2+3)-6;
}
while(fx1*fx2>0);
do
{x0=(x1+x2)/2;
fx0=x0*((2*x0-4)*x0+3)-6;
if((fx0*fx1)<0)
   {x2=x0;
   fx2=fx0;
   }
else
   {x1=x0;
   fx1=fx0;
   }
}
while(fabs(fx0)>=1e-5);
printf("x0=%6.2f\n",x0);
}
6.14打印图案
main()
{int i,j,k;
for(i=0;i<=3;i++)
{for(j=0;j<=2-i;j++)
   printf(" ");
for(k=0;k<=2*i;k++)
   printf("*");
printf("\n");
}
  for(i=0;i<=2;i++)
{for(j=0;j<=i;j++)
   printf(" ");
for(k=0;k<=4-2*i;k++)
   printf("*");
printf("\n");
}
}
6.15乒乓比赛
main()
{
char i,j,k;
for(i='x';i<='z';i++)
for(j='x';j<='z';j++)
{
if(i!=j)
for(k='x';k<='z';k++)
{
if(i!=k&&j!=k)
{if(i!='x' && k!='x' && k! ='z')
printf("顺序为:\na-%c\tb--%c\tc--%c\n",i,j,k);
}
}
  }
}
C语言设计谭浩强第三版的课后习题答案
7.1用筛选法求100之内的素数.
#include
#define N 101
main()
{int i,j,line,a[N];
for(i=2;ifor(i=2;ifor(j=i+1;j  {if(a[i]!=0 && a[j]!=0)
   if(a[j]%a[i]==0)
a[j]=0;
printf("\n");
for(i=2,line=0;i{  if(a[i]!=0)
{printf("%5d",a[i]);
line++;
if(line==10)
{printf("\n");
line=0;}
}
}
7.2用选择法对10个数排序.
#define N 10
main()
{ int i,j,min,temp,a[N];
printf("请输入十个数:\n");
for (i=0;i{ printf("a[%d]=",i);
scanf("%d",&a[i]);
}
printf("\n");
for(i=0;i  printf("%5d",a[i]);
printf("\n");
for (i=0;i{  min=i;
for(j=i+1;j    if(a[min]>a[j]) min=j;
   temp=a[i];
   a[i]=a[min];
   a[min]=temp;
}
printf("\n排序结果如下:\n");
for(i=0;iprintf("%5d",a[i]);
}
7.3对角线和:
main()
{
float a[3][3],sum=0;
int i,j;
printf("请输入矩阵元素:\n");
for(i=0;i<3;i++)
  for(j=0;j<3;j++)
scanf("%f",&a[i][j]);
  for(i=0;i<3;i++)
sum=sum+a[i][i];
printf("对角元素之和=6.2f",sum);
}
7.4插入数据到数组
main()
{int a[11]={1,4,6,9,13,16,19,28,40,100};
int temp1,temp2,number,end,i,j;
printf("初始数组如下:");
for (i=0;i<10;i++)
printf("%5d",a[i]);
printf("\n");
printf("输入插入数据:");
scanf("%d",&number);
end=a[9];
if(number>end)
a[10]=number;
else
{for(i=0;i<10;i++)
{ if(a[i]>number)
{temp1=a[i];
a[i]=number;
for(j=i+1;j<11;j++)
{temp2=a[j];
a[j]=temp1;
temp1=temp2;
}
break;
}
   }
}
for(i=0;j<11;i++)
printf("a%6d",a[i]);
}
7.5将一个数组逆序存放。
#define N 5
main()
{ int a[N]={8,6,5,4,1},i,temp;
printf("\n 初始数组:\n");
for(i=0;iprintf("%4d",a[i]);
for(i=0;i{  temp=a[i];
a[i]=a[N-i-1];
a[N-i-1]=temp;
}
printf("\n 交换后的数组:\n");
for(i=0;i printf("%4d",a[i]);
}
7.6杨辉三角
#define N 11
main()
{ int i,j,a[N][N];
  for(i=1;i  {a[i][i]=1;
a[i][1]=1;
  }
  for(i=3;i for(j=2;j<=i-1;j++)
a[i][j]=a[i01][j-1]+a[i-1][j];
for(i=1;i {  for(j=1;j<=i;j++)
printf("%6d",a[i][j];
printf("\n");
}
printf("\n");
}
7.8鞍点
#define N 10
#define M 10
main()
{ int i,j,k,m,n,flag1,flag2,a[N][M],max,maxi,maxj;
printf("\n输入行数n:");
scanf("%d",&n);
printf("\n输入列数m:");
scanf("%d",&m);

for(i=0;i {  printf("第%d行?\n",i);
for(j=0;j scanf("%d",&a[i][j];
}
for(i=0;i {  for(j=0;j    printf("%5d",a[i][j]);
pritf("\n");
}
flag2=0;
for(i=0;i {  max=a[i][0];
for(j=0;j if(a[i][j]>max)
{  max=a[i][j];
maxj=j;
}
for (k=0,flag1=1;k if(max>a[k][max])
  flag1=0;
if(flag1)
{ printf("\n第%d行,第%d列的%d是鞍点\n",i,maxj,max);
flag2=1;
}
}
if(!flag2)
printf("\n 矩阵中无鞍点!  \n");
}

7.9变量说明:top,bott:查找区间两端点的下标;loca:查找成功与否的开关变量.
#include
#define N 15
main()
{ int i,j,number,top,bott,min,loca,a[N],flag;
  char c;
  printf("输入15个数(a[i]>[i-1])\n);
  scanf("%d",&a[0]);
  i=1;
  while(i  {  scanf("%d",&a[i]);
   if(a[i]>=a[i-1])
i++;
esle
{printf("请重输入a[i]");
printf("必须大于%d\n",a[i-1]);
}
  }
  printf("\n");
  for(i=0;i    printf("%4d",a[i]);
  printf("\n");

  flag=1;
  while(flag)
  {
printf("请输入查找数据:");
  scanf("%d",&number);
  loca=0;
  top=0;
  bott=N-1;
  if((numbera[N-1]))
loca=-1;
  while((loca==0)&&(top<=bott))
  { min=(bott+top)/2;
if(number==a[min])
{ loca=min;
   printf("%d位于表中第%d个数\n",number,loca+1);
}
else if(number    bott=min-1;
else
   top=min+1;
  }
  if(loca==0||loca==-1)
printf("%d不在表中\n",number);
  printf("是否继续查找?Y/N!\n");
  c=getchar();
if(c=='N'||c=='n')
flag=0;
}
}

7.10
main()
{ int i,j,uppn,lown,dign,span,othn;
  char text[3][80];
  uppn=lown=dign=span=othn=0;
  for(i=0;i<3;i++)
  {  printf("\n请输入第%d行:\n",i);
   gets(text[i]);
   for(j=0;j<80 && text[i][j]!='\0';j++)
   {if(text[i][j]>='A' && text[i][j]<='Z')
uppn+=1;
else if(text[i][j]>='a' && text[i][j]<='z')
lown+=1;
else if(text[i][j]>='1' && text[i][j]<='9')
dign+=1;
else if(text[i][j]=' ')
span+=1;
else
othn+=1;
   }
  }
  for(i=0;i<3;i++)
printf("%s=n",text[i]);
  printf("大写字母数:%d\n",uppn);
  printf("小写字母数:%d\n",lown);
  printf("数字个数:%d\n",dign);
  printf("空格个数:%d\n",span);
  printf("其它字符:%d\n",othn);
}

7.11
main()
  {static char a[5]={'*','*','*','*','*'};
int i,j,k;
char space=' ';
  for(i=0;i<=5;i++)
{printf("\n");
for(j=1;j<=3*i;j++)
printf("%lc",space);
for(k=0;k<=5;k++)
printf("%3c",a[k];
}
}
7.12
#include
main()
{int i,n;
char ch[80],tran[80];
printf("请输入字符:");
gets(ch);
printf("\n密码是%c",ch);
i=0;
while(ch[i]!='\0')
{if((ch[i]>='A')&&(ch[i]<='Z'))
tran[i]=26+64-ch[i]+1+64;
else if((ch[i]>='a')&&(ch[i]<='z'))
tran[i]=26+96-ch[i]+1+96;
else
tran[i]=ch[i];
  i++;
}
n=i;
printf("\n原文是:");
for(i=0;iputchar(tran[i]);
}
7.13
main()
  {
  char s1[80],s2[40];
  int i=0,j=0;
  printf("\n请输入字符串1:");
  scanf("%s",s1);
  printf("\n请输入字符串2:");
  scanf("%s",s2);
  while(s1[i]!='\0')
i++;
while(s2[j]!='\0')
  s1[i++]=s2[j++];
s1[i]='\0';
printf("\n连接后字符串为:%s",s1);
  }

7.14
#include
main()
{int i,resu;
char s1[100],s2[100];
printf("请输入字符串1:\n");
gets(s1);
printf("\n 请输入字符串2:\n");
gets(s2);
i=0;
while((s1[i]==s2[i]) && (s1[i]!='\0'))i++;
if(s1[i]=='\0' && s2[i]=='\0')resu=0;
else
resu=s1[i]-s2[i];
printf(" %s与%s比较结果是%d",s1,s2,resu);
}
7.15
#include
main()
  {
  char from[80],to[80];
  int i;
  printf("请输入字符串");
  scanf("%s",from);
  for(i=0;i<=strlen(from);i++)
to[i]=from[i];
  printf("复制字符串为:%s\n",to);
  }

第八章函数
8.1(最小公倍数=u*v/最大公约数.)
hcf(u,v)
int u,v;
(int a,b,t,r;
if(u>v)
  {t=u;u=v;v=t;}
a=u;b=v;
while((r=b%a)!=0)
{b=a;a=r;}
  return(a);
  }
lcd(u,v,h)
int u,v,h;
{int u,v,h,l;
scanf("%d,%d",&u,&v);
h=hcf(u,v);
printf("H.C.F=%d\n",h);
l=lcd(u,v,h);
printf("L.C.d=%d\n",l);
}
  {return(u*v/h);}
main()
{int u,v,h,l;
scanf("%d,%d",&u,&v);
h=hcf(u,v);
printf("H.C.F=%d\n",h);
l=lcd(u,v,h);
printf("L.C.D=%d\n",l);
}

8.2求方程根
#include
float x1,x2,disc,p,q;
greater_than_zero(a,b)
float a,b;
{
x1=(-b+sqrt(disc))/(2*a);
x2=(-b-sqrt(disc))/(2*a);
}
equal_to_zero(a,b)
float a,b;
{x1=x2=(-b)/(2*a);}
smaller_than_zero(a,b)
float a,b;
{p=-b/(2*a);
q=sqrt(disc)/(2*a);
}
main()
{
float a,b,c;
printf("\n输入方程的系数a,b,c:\n");
scanf("%f,%f,%f",&a,&b,&c);
printf("\n 方程是：%5.2f*x*x+%5.2f*x+%5.2f=0\n",a,b,c);
disc=b*b-4*a*c;
printf("方程的解是：\n");
if(disc>0)
{great_than_zero(a,b);
printf("X1=%5.2f\tX2=%5.2f\n\n",x1,x2);
}
else if(disc==0)
{
zero(a,b);
printf("X1=%5.2f\tX2=%5.2f\n\n",x1,x2);
}
else
{
small_than_zero(a,b,c);
printf("X1=%5.2f+%5.2fi\tX2=%5.2f-%2.2fi\n",p,q,p,q);
}
}
8.3素数
#include"math.h"
main()
{int number;
scanf("%d",&number);
if(prime(number))
printf("yes");
else
printf("no");
}
int prime(number)
int number;
{int flag=1,n;
for(n=2;n if(number%n==0)
   flag=0;
return(flag);
}

8.4
#define N 3
int array[N][N];
convert(array)
int array[3][3];
{ int i,j,t;
  for(i=0;i for(j=i+1;j { t=array[i][j];
array[i][j]=array[j][i];
array[j][i]=t;
}
}
main()
{
int i,j;
printf("输入数组元素:\n");
for(i=0;i for(j=0;j scanf("%d",&array[i][j];
printf("\n数组是:\n");
for(i=0;i { for(j=0;j printf("%5d",array[i][j]);
  printf("\n");
}
convert(array);
printf("转置数组是:\n");
for(i=0;i { for(j=0;j printf("%5d",array[i][j]);
printf("\n");
}
}

8.5
main()
{
char str[100];
  printf("输入字符串:\n");
  scanf("%s",str);
  inverse(str);
  printf("转换后的字符串是: %s\n",str);
}
inverse(str)
char str[];
{
char t;
int i,j;
for(i=0,j=strlen(str);i {
t=str[i];
str[i]=str[i-1];
str[i-1]=t;
}
}

8.6
char concatenate(string1,string2,string);
char string1[],string2[],string[];
{
int i,j;
for(i=0;string1[i]!='\0';i++)
  string[i]=string1[i];
for(j=0;string2[j]!='\0';j++)
string[i+j]=string2[j];
string[i+j]='\0';
}
main()
{
char s1[100],s2[100],s[100];
printf("\n输入字符串1：\n");
scanf("%s",s1);
printf("输入字符串2:\n");
scanf("%s",s2);
concatenate(s1,s2,s);
printf("连接后的字符串：%s\n",s);
}

8.8
main()
{
char str[80];
printf("请输入含有四个数字的字符串:\n");
scanf("%s",str);
insert(str);
}
insert(str)
char str[];
{
int i;
for(i=strlen(str);i>0;i--)
{ str[2*i]=str[i];
str[2*i-1]=' ';
}
printf("\n 结果是:\n %s",str);
}

8.9
#include"math.h"
int alph,digit,space,others;
main()
{char text[80];
gets(text);
alph=0,digit=0,space=0,others=0;
count(text);
printf("\nalph=%d,digit=%d,space=%d,others=%d\n",alph,digit,space,others);
}
count(str)
char str[];
{int i;
for(i=0;str[i]!='\0';i++)
if((str[i]>='a'&&str[i]<='z')||(str[i]>='A'&&str[i]<='Z'))
   alph++;
else if(str[i]>='0'&&str[i]<='9')
   digit++;
else if(strcmp(str[i],' ')==0)
   space++;
else
   others++;
}

8.10
int alphabetic(c);
char c;
{
  if((c>='a' && c<='z'||(c>='A' && c<='Z'))
return(1);
  else
return(0);
}

int longest (string)
char string[];
{
int len=0,i,length=0,flag=1,place,point;
for(i=0;i<=strlen(string);i++)
if(alphabctic(string[i]))
if(flag)
{
point=i;
flag=0;
}
else
len++;
else
{ flag=1;
  if len>length)
  {length=len;
place=point;
len=0;
}
}
   return(place);
  }
main()
{
int i;
char line[100];
printf("输入一行文本\n");
gets(line);
printf("\n最长的单词是:");
for(i=longest(line);alphabctic(line[i]);i++)
printf("%c",line[i];
printf("\n");
}

8.11
#include

#define N 10
char str[N];
main()
{
int i,flag;
for(flag=1;flag==1;)
{
printf("\n输入字符串,长度为10:\n");
scanf("%s",&str);
if(strlen(str)>N)
printf("超过长度,请重输!");
else
flag=0;
}
sort(str);
printf("\n 排序结果:");
for(i=0;i  printf("%c",str[i]);
}
sort(str)
char str[N];
{
int i,j;
char t;
for(j=1;j for(i=0;(i  if(str[i]>str[i+1])
  { t=str[i];
str[i]=str[i+1];
str[i+1]=t;
  }
}
8.12
#include
#include
float solut(a,b,c,d)
float a,b,c,d;
{float x=1,x0,f,f1;
do
{x0=x;
f=((a*x0+b)*x0+c)*x0+d;
f1=(3*a*x0+2*b)*x0+c;
x=x0-f/f1;
}
while(fabs(x-x0)>=1e-5);
return(x);
}
main()
{float a,b,c,d;
scanf("%f,%f,%f,%f",&a,&b,&c,&d);
printf("x=%10.7f\n",solut(a,b,c,d));
}
8.13
#include
main()
{int x,n;
float p();
scanf("%d,%d",&n,&x);
printf("P%d(%d)=%10.2f\n",n,x,p(n,x));
}
float p(tn,tx)
int tn,tx;
{if(tn==0)
return(1);
else if(tn==1)
return(tx);
else
return(((2*tn-1)*tx*p((tn-1),tx)-(tn-1)*p((tn-2),tx))/tn);
}
8.14
#include "stdio.h"
#define N 10
#define M 5
float score[N][M];
float a_stu[N],a_cor[M];
main()
{int i,j,r,c;
float h;
float s_diff();
float highest();
r=0;
c=1;
input_stu();
avr_stu();
avr_cor();
printf("\n  number  class  1  2  3  4  5  avr");
for(i=0;i {printf("\nNO%2d",i+1);
for(j=0;j    printf("%8.2f",score[i][j]);
printf("%8.2f",a_stu[i]);
}
printf("\nclassavr");
for(j=0;j printf("%8.2f",a_cor[j]);
h=highest(&r,&c);
printf("\n\n%8.2f %d %d\n",h,r,c);
printf("\n %8.2f\n",s_diff());
}
input_stu()
{int i,j;
float x;
for(i=0;i {for(j=0;j    {scanf("%f",&x);
   score[i][j]=x;
   }
}
}
avr_stu()
{int i,j;
float s;
for(i=0;i {for(j=0,s=0;j    s+=score[i][j];
a_stu[i]=s/5.0;
}
}
avr_cor()
{int i,j;
float s;
for(j=0;j {for(i=0,s=0;i    s+=score[i][j];
a_cor[j]=s/(float)N;
}
}
float highest(r,c)
int *r,*c;
{float high;
int i,j;
high=score[0][0];
for(i=0;i for(j=0;j    if(score[i][j]>high)
   {high=score[i][j];
      *r=i+1;
      *c=j+1;
      }
return(high);
}
float s_diff()
{int i,j;
float sumx=0.0,sumxn=0.0;
for(i=0;i {sumx+=a_stu[i]*a_stu[i];
sumxn+=a_stu[i];
}
return(sumx/N-(sumxn/N)*(sumxn/N));
}
8.15
#include
#define N 10
void input_e(num,name)
int num[];
char name[N][8];
{int i;
for(i=0;i {scanf("%d",&num[i]);
gets(name[i]);
}
}
void sort(num,name)
int num[];
char name[N][8];
{int i,j,min,temp1;
char temp2[8];
for(i=0;i {min=i;
for(j=i;j    if(num[min]>num[j])min=j;
temp1=num[i];
num[i]=num[min];
num[min]=temp1;
strcpy(temp2,name[i]);
strcpy(name[i],name[min]);
strcpy(name[min],temp2);
}
for(i=0;i printf("\n%5d%10s",num[i],name[i]);
}
void search(n,num,name)
int n,num[];
char name[N][8];
{int top,bott,min,loca;
loca=0;
top=0;
bott=N-1;
if((nnum[N-1]))
loca=-1;
while((loca==0)&&(top<=bott))
{min=(bott+top)/2;
if(n==num[min])
   {loca=min;
   printf("number=%d,name=%s\n",n,name[loca]);
   }
else if(n    bott=min-1;
else
   top=min+1;
}
if(loca==0||loca==-1)
printf("number=%d is not in table\n",n);
}
main()
{int num[N],number,flag,c,n;
char name[N][8];
input_e(num,name);
sort(num,name);
for(flag=1;flag;)
{scanf("%d",&number);
search(number,num,name);
printf("continue?Y/N!");
c=getchar();
if(c=='N'||c=='n')
   flag=0;
}
}

8.16
#include
#define MAX 1000
main()
{ int c,i,flag,flag1;
  char t[MAX];
i=0;
flag=0;
flag1=1;
printf("\n输入十六进制数:");
while((c=getchar())!='\0'&&i { if c>='0' && c<='9'||c>='a'&&c<='f'||c>='A'&&c<='F')
{flag=1;
t[i++]=c;
}
else if(flag)
{
t[i]='\0';
printf("\n 十进制数%d\n",htoi(t));
printf("继续吗?");
c=getchar();
if(c=='N'||c=='n')
  flag1=0;
else
{flag=0;
  i=0;
  printf("\n 输入十六进制数:");
}
}
}
}
htoi(s)
char s[];
{ int i,n;
  n=0;
  for(i=0;s[i]!='\0';i++)
  {if(s[i]>='0'&&s[i]<='9')
n=n*16+s[i]-'0';
if(s[i]>='a'&&s[i]<='f')
n=n*16+s[i]-'a'+10;
if(s[i]>='A'&&s[i]<='F')
n=n*16+s[i]-'A'+10;
}
return(n);
}

8.17
#include
void counvert(n)
int n;
{ int i;
if((i=n/10)!=0)
  convert(i);
putchar(n%10+'0');
}
main()
{ int number;
  printf("\n 输入整数:");
  scanf("%d",&number);
  printf("\n 输出是: ");
  if(number<0)
  { putchar('-');
number=-number;
  }
convert(number);
}

8.18
main()
{
  int year,month,day;
  int days;
  printf("\n 请输入日期(年,月,日)\n");
  scanf("%d,%d,%d",&year,&month,&day);
  printf("\n %d年%d月%d日",year,month,day);
  days=sum_day(month,day);
  if(leap(year)&&month>=3)
days=days+1;
  printf("是该年的%d天.\n",days);
}
static int day_tab[13]={0,31,28,31,30,31,30,31,31,30,31,30,31}
int(sum_day(month,day)
int month,day;
  {
  int i;
  for(i=1;i day+=day_tab[i];
  return(day);
  }
int leap(year)
int year;
{
int leap;
leap=year%4==0&&year%100!=0||year%400==0;
return(leap);
}
第九章编译预处理
9.1
#define SWAP(a,b) t=b;b=a;a=t
main()
{
int a,b,t;
printf("请输入两个整数 a,b:");
scanf("%d,%d",&a,&b);
SWAP(a,b);
printf("交换结果为:a=%d,b=%d\n",a,b);
}

9.2
#define SURPLUS(a,b) ((a)%(b))
main()
{
int a,b;
printf(" 请输入两个整数 a,b:");
scanf("%d,%d",&a,&b);
printf("a,b相除的余数为:%d\n",SURPLUS(a,b));
}

9.3
#include
#defin S(a,b,c) ((a+b+c)/2)
#define AREA(a,b,c) (sqrt(S(a,b,c)*(S(a,b,c)-a)*(S(a,b,c)-b)*(s(a,b,c)-
c)))
main()
{
float a,b,c;
  printf("请输入三角形的三条边:");
  scanf("%f,%f,%f",&a,&b,&c);
  if(a+b>c && a+c>b && b+c>a)
printf("其面积为:%8.2f.\n",AREA(a,b,c));
  else
printf("不能构成三角形!");
}

9.4
#define LEAP_YEAR(y) (y%4==0) && (y%100!=0)||(y%400==0)
main()
{
int year;
printf("\n请输入某一年:");
scanf("%d",&year);
if(LEAP_YEAR(year))
  printf("%d  是闰年.\n",year);
else
  printf("%d  不是闰年.\n",year);
}

9.5解:展开后:
printf("＆#118alue=%format\t",x);
printf("＆#118alue=%format\t",x);putchar('\n');
printf("＆#118alue=%format\t");printf("＆#118alue=%format\t",x2);putchar('\n');
输出结果:
＆#118alue=5.000000ormat ＆#118alue=5.000000ormat
＆#118alue=3.000000ormat ＆#118alue=8.000000ormat

9.8
main()
  {
  int a,b,c;
  printf("请输入三个整数:");
  scanf("%d,%d,%d",&a,&b,&c);
  printf("三个之中最大值为:%d\n",max(a,b,c));
  }
max(x,y,z)
int x,y,z;
{
int t;
t=(x>y? x:y);
return(t>z? t:z);
}

9.10
#include
#define MAX 80
#define CHANGE 1
main()
{
char str[MAX];
int i;
printf("请输入文本行:\n");
scanf("%s",str);
#if(CHANGE)
  {
  for (i=0;i  {
  if(str[i]!='\0'
if(str[i]>='a' && str[i]<'z' || str[i]>='A'&&str[i]<'Z')
str[i]+=1;
else if(str[i]=='z' || str[i]=='Z')
str[i]-=25;
  }
}
#endif
printf("输出电码为:\n%s",str);
}
第十章  指针
10.1
main()
{int n1,n2,n3;
int *p1,*p2,*p3;
scanf("%d,%d,%d",&n1,&n2,&n3);
p1=&n1;
p2=&n2;
p3=&n3;
if(n1>n2)swap(p1,p2);
if(n1>n3)swap(p1,p3);
if(n2>n3)swap(p2,p3);
printf("%d,%d,%d\n",n1,n2,n3);
}
swap(p1,p2)
int *p1,*p2;
{int p;
p=*p1;*p1=*p2;*p2=p;
}
10.2
main()
{char *str1[20],*str2[20],*str3[20];
char swap();
scanf("%s",str1);
scanf("%s",str2);
scanf("%s",str3);
if(strcmp(str1,str2)>0)swap(str1,str2);
if(strcmp(str1,str3)>0)swap(str1,str3);
if(strcmp(str2,str3)>0)swap(str2,str3);
printf("%s\n%s\n%s\n",str1,str2,str3);
}
char swap(p1,p2)
char *p1,*p2;
{char *p[20];
strcpy(p,p1);
strcpy(p1,p2);
strcpy(p2,p);
}
10.3
main()
{int number[10];
input(number);
max_min_＆#118alue(number);
output(number);
}
input(number)
int number[10];
{int i;
for(i=0;i<10;i++)
scanf("%d",&number[i]);
}
max_min_＆#118alue(number)
int number[10];
{int *max,*min;
int *p,*end;
end=number+10;
max=min=number;
for(p=number+1;p if(*p>*max)max=p;
else if(*p<*min)min=p;
*p=number[0];
number[0]=*min;
*min=*p;
*p=number[9];
number[9]=*max;
*max=*p;
return;
}
output(number)
int number[10];
{int *p;
for(p=number;p printf("%d,",*p);
printf("%d\n",*p);
}
10.4
main()
{int number[20],n,m,i;
scanf("%d",&n);
scanf("%d",&m);
for(i=0;i scanf("%d",&number[i]);
move(number,n,m);
for(i=0;i printf("%8d",number[i]);
}
move(array,n,m)
int array[20],n,m;
{int *p,end;
end=*(array+n-1);
for(p=array+n-1;p>array;p--)
*p=*(p-1);
*array=end;
m--;
if(m>0)move(array,n,m);
}
10.5
#define nmax 50
main()
{int i,k,m,n,num[nmax],*p;
scanf("%d",&n);
p=num;
for(i=0;i *(p+i)=i+1;
i=k=m=0;
while(m {if(*(p+i)!=0)k++;
if(k==3)
   {*(p+i)=0;
   k=0;
   m++;
   }
i++;
if(i==n)i=0;
}
while(*p==0)p++;
printf("%d",*p);
}
10.6
main()
{int len;
char *str[20];
scanf("%s",str);
len=length(str);
printf("\nlen=%d\n",len);
}
length(p)
char *p;
{int n=0;
while(*p!='\0')
{n++;p++;}
return(n);
}
10.7
main()
{int m;
char *str1[20],*str2[20];
scanf("%s",str1);
scanf("%d",&m);
if(strlen(str1) printf("error");
else
{copystr(str1,str2,m);
printf("%s",str2);
}
}
copystr(p1,p2,m)
char *p1,*p2;
int m;
{int n=0;
while(n {n++;p1++;}
while(*p1!='\0')
{*p2=*p1;
p1++;
p2++;
}
*p2='\0';
}
10.8
#include"stdio.h"
main()
{int cle=0,sle=0,di=0,wsp=0,ot=0,i;
char *p,s[20];
for(i=0;i<20;i++)s[i]=0;
i=0;
while((s[i]=getchar())!='\n')i++;
p=s;
while(*p!='\n')
{if(*p>='a'&&*p<='z')
   ++sle;
else if(*p>='A'&&*p<='Z')
   ++cle;
else if(*p==' ')
   ++wsp;
else if(*p>='0'&&*p<='9')
   ++di;
else
   ++ot;
p++;
}
printf("sle=%d,cle=%d,wsp=%d,di=%d,ot=%d\n",sle,cle,wsp,di,ot);
}
10.9
main()
{int a[3][3],*p,i;
for(i=0;i<3;i++)
scanf("%d,%d,%d",a[i][0],a[i][1],a[i][2]);
p=a;
move(p);
for(i=0;i<3;i++)
printf("%d  %d  %d\n",a[i][0],a[i][1],a[i][2]);
}
move(pointer)
int *pointer;
{int i,j,t;
for(i=0;i<2;i++)
for(j=i+1;j<3;j++)
{t=*(pointer+3*i+j);
*(pointer+3*i+j)=*(pointer+3*j+i);
*(pointer+3*j+i)=t;
}
}
10.10
main()
{int a[5][5],*p,i,j;
for(i=0;i<5;i++)
for(j=0;j<5;j++)
scanf("%d",&a[i][j]);
p=a;
change(p);
for(i=0;i<5;i++)
{printf("\n");
for(j=0;j<5;j++)
   printf("%8d",a[i][j]);
}
}
change(p)
int *p;
{int i,j,change;
int *pmax,*pmin;
pmax=p;
pmin=p;
for(i=0;i<5;i++)
for(j=0;j<5;j++)
   {if(*pmax<*(p+5*i+j))pmax=p+5*i+j;
   if(*pmin>*(p+5*i+j))pmin=p+5*i+j;
   }
change=*(p+12);
*(p+12)=*pmax;
*pmax=change;
change=*p;
*p=*pmin;
*pmin=change;
pmin=p+1;
for(i=0;i<5;i++)
for(j=0;j<5;j++)
   if(((p+5*i+j)!=p)&&(*pmin>*(p+5*i+j)))pmin=p+5*i+j;
change=*(p+4);
*(p+4)=*pmin;
*pmin=change;
pmin=p+1;
for(i=0;i<5;i++)
for(j=0;j<5;j++)
   if(((p+5*i+j)!=(p+4))&&((p+5*i+j)!=p)&&(*pmin>*(p+5*i+j)))
      pmin=p+5*i+j;
change=*(p+20);
*(p+20)=*pmin;
*pmin=change;
pmin=p+1;
for(i=0;i<5;i++)
for(j=0;j<5;j++)
   if(((p+5*i+j)!=p)&&((p+5*i+j)!=(p+4))&&((p+5*i+j)!=(p+20))
         &&(*pmin>*(p+5*i+j)))pmin=p+5*i+j;
change=*(p+24);
*(p+24)=*pmin;
*pmin=change;
}
10.11
main()
{int i;
char *p,str[10][10];
for(i=0;i<10;i++)
scanf("%s",str[i]);
p=str;
sort(p);
for(i=0;i<10;i++)
printf("%s\n",str[i]);
}
sort(p)
char *p;
{int i,j;
char s[10],*smax,*smin;
for(i=0;i<10;i++)
{smax=p+10*i;
for(j=i+1;j<10;j++)
   {smin=p+10*j;
   if(strcmp(smax,smin)>0)
      {strcpy(s,smin);
      strcpy(smin,smax);
      strcpy(smax,s);
      }
   }
}
}
10.12
#define MAX 20
main()
{int i;
char *pstr[10],str[10][MAX];
for(i=0;i<10;i++)
pstr[i]=str[i];
for(i=0;i<10;i++)
scanf("%s",pstr[i]);
sort(pstr);
for(i=0;i<10;i++)
printf("%s\n",pstr[i]);
}
sort(pstr)
char *pstr[10];
{int i,j;
char *p;
for(i=0;i<10;i++)
{for(j=i+1;j<10;j++)
   {if(strcmp(*(pstr+i),*(pstr+j))>0)
      {p=*(pstr+i);
      *(pstr+i)=*(pstr+j);
      *(pstr+j)=p;
      }
   }
}
}
10.13
#include"math.h"
main()
{int n=20;
float a,b,a1,b1,a2,b2,c,(*p)(),jiff();
scanf("%f,%f",&a,&b);
scanf("%f,%f",&a1,&b1);
scanf("%f,%f",&a2,&b2);
p=sin;
c=jiff(a,b,n,p);
printf("sin=%f\n",c);
p=cos;
c=jiff(a1,b1,n,p);
printf("cos=%f\n",c);
p=exp;
c=jiff(a2,b2,n,p);
printf("exp=%f\n",c);
}
float jiff(a,b,n,p)
float a,b,(*p)();
int n;
{int i;
float x,f,h,area;
h=(b-a)/n;
x=a;
area=0;
for(i=1;i<=n;i++)
{x=x+h;
area=area+(*p)(x)*h;
}
return(area);
}
10.14
main()
{int i,n,num[20];
char *p;
scanf("%d",&n);
for(i=0;i scanf("%d",&num[i]);
p=num;
sort(p,n);
for(i=0;i printf("%8d",num[i]);
}
sort(p,m)
char *p;
int m;
{int i;
char change,*p1,*p2;
for(i=0;i {p1=p+i;
p2=p+(m-1-i);
change=*p1;
*p1=*p2;
*p2=change;
}
}
10.15
main()
{int i,j,*pnum,num[4];
float score[4][5],aver[4],*psco,*pave;
char course[5][10],*pcou;
pcou=course[0];
for(i=0;i<5;i++)
scanf("%s",pcou+10*i);
printf("number");
for(i=0;i<5;i++)
printf(",%s",pcou+10*i);
printf("\n");
psco=score;
pnum=num;
for(i=0;i<4;i++)
{scanf("%d",pnum+i);
for(j=0;j<5;j++)
   scanf(",%f",psco+5*i+j);
}
pave=aver;
printf("\n");
avsco(psco,pave);
avcour1(pcou,psco);
printf("\n");
fali2(pcou,pnum,psco,pave);
printf("\n");
good(pcou,pnum,psco,pave);
}
avsco(psco,pave)
float *psco,*pave;
{int i,j;
float sum,average;
for(i=0;i<4;i++)
{sum=0;
for(j=0;j<5;j+)
   sum+=(*(psco+5*i+j));
average=sum/5;
*(pave+i)=average;
}
}
avcour1(pcou,psco)
char *pcou;
float *psco;
{int i;
float sum,average1;
sum=0;
for(i=0;i<4;i++)
sum+=(*(psco+5*i))
average1=sum/4;
printf("%s    %5.2f\n",pcou,average1);
}
fali2(pcou,pnum,psco,pave)
char *pcou;
int *pnum;
float *psco,*pave;
{int i,j,k,label;
printf("\nnumber\n");
for(i=0;i<5;i++)
printf("%-8s",pcou+10*i);
printf("\naverage\n");
for(i=0;i<4;i++)
{label=0;
for(j=0;j<5;j++)
   if(*(psco+5*i+j)<60.0)label++;
if(label>=2)
   {printf("%-8d",*(pnum+i));
   for(k=0;k<5;k++)
      printf("%-8.2f",*(psco+5*i+k));
   printf("%-8.2f",*(pave+i));
   }
}
}
good(pcou,pnum,psco,pave)
char *pcou;
int *pnum;
float *psco,*pave;
{int i,j,k,label;
printf("number");
for(i=0;i<5;i++)
printf("%-8s",pcou+10*i);
printf("average");
for(i=0;i<4;i++)
{label=0;
for(j=0;j<5;j++)
   if(*(psco+5*i+j)>=85.0)label++;
if((label>=5)||(*(pave+i)>=90))
   {printf("%-8d",*(pnum+i));
   for(k=0;k<5;k++)
      printf("%-8.2f",*(psco+5*i+k));
   printf("%-8.2f",*(pave+i));
   }
}
}
10.16
#include"stdio.h"
main()
{char str[50],*pstr;
int i,j,k,m,e10,digit,ndigit,a[10],*pa;
gets(str);
pstr=str;
pa=a;
ndigit=0;
i=j=0;
while(*(pstr+i)!='\0')
{if((*(pstr+i)>='0')&&(*(pstr+i)<='9'))
   j++;
else
   {if(j>0)
      {digit=*(pstr+i-1)-48;
      k=1;
      while(k          {e10=1;
         for(m=1;m<=k;m++)
            e10=e10*10;
         digit+=(*(pstr+i-1-k)-48)*e10;
         k++;
         }
         *pa=digit;
         ndigit++;
         pa++;
         j=0;
      }
      }
   i++;
   }
if(j>0)
{digit=*(pstr+i-1)-48;
k=1;
while(k    {e10=1;
   for(m=1;m<=k;m++)
      e10=e10*10;
   digit+=(*(pstr+i-1-k)-48)*e10;
   k++;
   }
   *pa=digit;
   ndigit++;
   j=0;
}
printf("ndigit=%d\n",ndigit);
j=0;
pa=a;
for(j=0;j printf("%d",*(pa+j));
}
10.17
main()
{int m;
char str1[20],str2[20],*p1,*p2;
scanf("%s",str1);
scanf("%s",str2);
p1=str1;
p2=str2;
m=strcmp(p1,p2);
printf("%d\n",m);
}
strcmp(p1,p2)
char *p1,*p2;
{int i=0;
while(*(p1+i)==*(p2+i))
if(*(p+i++)=='\0')return(0);
return(*(p1+i)-*(p2+i));
}
10.18
main()
{static char *mname[13]={"illeagl","January","February","March",
"April","May","June","July","August","September","October",
"November","December"};
int n;
scanf("%d",&n);
if((n>=1)&&(n<=12))
printf("%s\n",*(mname+n));
else
printf("error");
}
10.20
main()
{int i;
char **p,*pstr[5],str[5][10];
for(i=0;i<5;i++)
pstr[i]=str[i];
for(i=0;i<5;i++)
scanf("%s",pstr[i]);
p=pstr;
sort(p);
for(i=0;i<5;i++)
printf("%s\n",pstr[i]);
}
sort(p)
char **P;
{int i,j;
char *pchange;
for(i=0;i<5;i++)
{for(j=i+1;j<5;j++)
   {if(strcmp(*(p+i),*(p+j))>0)
      {pchange=*(p+i);
      *(p+i)=*(p+j);
      *(p+j)=pchange;
      }
   }
}
}
10.21
main()
{int i,n,digit[20],**p,*pstr[20];
scanf("%d",&n);
for(i=0;i pstr[i]=&digit[i];
for(i=0;i scanf("%d",pstr[i]);
p=pstr;
sort(p,n);
for(i=0;i printf("%d ",*pstr[i]);
}
sort(p,n)
int **p,n;
{int i,j,*pchange;
for(i=0;i {for(j=i+1;j    {if(**(p+i)>**(p+j))
      {pchange=*(p+i);
      *(p+i)=*(p+j);
      *(p+j)=pchange;
      }
   }
}
}
第十一章  结构体与共用体
11.1
struct
  {int year;
int month;
int day;
  }date;
main()
{int days;
scanf("%d,%d,%d",&date.year,&date.month,&date.day);
switch(date.month)
{case 1:days=date.day;break;
case 2:days=date.day+31;break;
case 3:days=date.day+59;break;
case 4:days=date.day+90;break;
case 5:days=date.day+120;break;
case 6:days=date.day+151;break;
case 7:days=date.day+181;break;
case 8:days=date.day+212;break;
case 9:days=date.day+243;break;
case 10:days=date.day+273;break;
case 11:days=date.day+304;break;
case 12:days=date.day+334;break;
}
if((date.year%4==0&&date.year%100!=0||date.year%400==0)
                        &&date.month>=3)
days+=1;
printf("days=%d\n",days);
}
11.2
struct dt
  {int year;
int month;
int day;
  }date;
main()
{
scanf("%d,%d,%d",&date.year,&date.month,&date.day);
printf("\n%d\n",days(date.year,date.month,date.day));
}
days(year,month,day)
int year,month,day;
{int daysum=0,i;
static int daytab[13]={0,31,28,31,30,31,30,31,31,30,31,30,31}
for(i=1;i daysum+=daytab[i];
daysum+=day;
if((year%4==0&&year%100!=0||year%400==0)&&month>=3)
daysum+=1;
return(daysum);
}
11.3
11.4
#define N 5
struct student
  {char num[6];
char name[8];
int score[4];
}stu[N];
main()
{
input(stu);
print(stu);
}
input(stu)
struct student stu[];
{int i,j;
for(i=0;i {printf("number");
scanf("%s",stu[i].num);
printf("name");
scanf("%s",stu[i].name);
for(j=0;j<3;j++)
   {printf("\nscore\n");
   scanf("%d",&stu[i].score[j]);
   }
printf("\n");
}
}
print(stu)
struct student stu[];
{int i,j;
printf("\nnumber name  score1  score2  score3  \n");
for(i=0;i {printf("%8s%10s",stu[i].num,stu[i].name);
for(j=0;j<3;j++)
   printf("%7d",stu[i].score[j]);
printf("\n");
}
}
11.5
struct student
  {char num[6];
char name[8];
int score[4];
float avr;
}stu[5];
main()
{int i,j,max,maxi,sum;
float average;
for(i=0;i<5;i++)
{printf("number");
scanf("%s",stu[i].num);
printf("name");
scanf("%s",stu[i].name);
for(j=0;j<3;j++)
   {printf("\nscore\n");
   scanf("%d",&stu[i].score[j]);
   }
}
average=0;
max=0;
maxi=0;
for(i=0;i<5;i++)
{sum=0;
for(j=0;j<3;j++)
   sum+=stu[i].score[j];
stu[i].avr=sum/3.0;
average+=stu[i].avr;
if(sum>max)
   {max=sum;
   maxi=i;
   }
}
average/=5;
printf("number name  score1  score2  score3  average\n");
for(i=0;i<5;i++)
{printf("%8s%10s",stu[i].num,stu[i].name);
for(j=0;j<3;j++)
   printf("%7d",stu[i].score[j]);
printf("%6.2f\n",stu[i].avr);
}
printf("average=%5.2f\n",average);
printf("The best student is %s,sum=%d\n",stu[maxi].name,max);
}

zan