Mathematica 24点程序！

cjilyy

f[x1_, s1_, x2_, s2_, x3_, s3_, x4_] :=
Module[{result, i},
  result = {HoldForm[(x1~s1~x2)~s2~(x3~s3~x4)],
' M5 D, }, j2 y    HoldForm[x1~s1~(x2~s2~x3~s3~x4)],
0 [3 A, ?; u7 p3 m" t1 ~    HoldForm[x1~s1~x2~s2~(x3~s3~x4)],
) D2 m+ H3 ^8 @. A& ~    HoldForm[(x1~s1~x2~s2~x3)~s3~x4],
. r8 q, s+ b/ ^( Z    HoldForm[x1~s1~(x2~s2~x3)~s3~x4],
    HoldForm[(x1~s1~(x2~s2~x3))~s3~x4],
+ f4 \+ Q5 `( b2 B6 s# y* j; V3 H: p    HoldForm[x1~s1~(x2~s2~(x3~s3~x4))]};
  result = Union[result];
5 U# c7 r6 W( q' J  For[i = 1, i <= Length[result], i++,
6 h1 ?1 j$ Q7 g6 F4 E1 x   If[ReleaseHold[result[[i]]] == 24, Print[result[[i]], "=24"];
6 l5 B/ d5 h6 \: {     (*Print[TreeForm[result[[i]],DirectedEdges->True]]*);];];]
' w# b+ L. V1 w9 ]9 L  P
fs[x1_, x2_, x3_, x4_] :=
$ E3 ~! X3 I! o: C$ {/ D4 \ Module[{result, s, sym, num, i, j}, Off[Divide::infy];
  Off[Part::partw];
6 b6 Z9 X. |/ D* Z6 U# ~- _+ E* L  Off[Divide::indet];
9 h$ J( a- U5 C( y* H; L  s = {Plus, Subtract, Times, Divide};
  sym = Flatten[
, Y+ [4 W5 |! o# c    Table[{s[[i]], s[[j]], s[[k]]}, {i, 4}, {j, 4}, {k, 4}], 2];
  sym = Union[sym];
  num = Permutations[{x1, x2, x3, x4}];
5 {8 s( k3 u# Z  Do[f[num[[i, 1]], sym[[j, 1]], num[[i, 2]], sym[[j, 2]],
    num[[i, 3]], sym[[j, 3]], num[[i, 4]]], {i, Length[num]}, {j,
    Length[sym]}]]
  a3 d) N; b. B/ R: e0 E/ {
fs[3, 3, 8, 8]