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)],
- u* n& z' ^/ i1 k5 O: B    HoldForm[x1~s1~(x2~s2~x3~s3~x4)],
    HoldForm[x1~s1~x2~s2~(x3~s3~x4)],
    HoldForm[(x1~s1~x2~s2~x3)~s3~x4],
    HoldForm[x1~s1~(x2~s2~x3)~s3~x4],
! ~! o1 f1 Y* R    HoldForm[(x1~s1~(x2~s2~x3))~s3~x4],
0 X/ j+ A9 L1 t: x    HoldForm[x1~s1~(x2~s2~(x3~s3~x4))]};
4 D1 Q0 A: A: E' P  result = Union[result];
# @: i4 c- J& @4 Y/ X1 V5 v( y  For[i = 1, i <= Length[result], i++,
   If[ReleaseHold[result[[i]]] == 24, Print[result[[i]], "=24"];
     (*Print[TreeForm[result[[i]],DirectedEdges->True]]*);];];]

! n+ L/ v3 r! r2 [, Hfs[x1_, x2_, x3_, x4_] :=
Module[{result, s, sym, num, i, j}, Off[Divide::infy];
  Off[Part::partw];
  Off[Divide::indet];
  s = {Plus, Subtract, Times, Divide};
+ o9 }( g0 S* M( ^  sym = Flatten[
    Table[{s[[i]], s[[j]], s[[k]]}, {i, 4}, {j, 4}, {k, 4}], 2];
  sym = Union[sym];
  num = Permutations[{x1, x2, x3, x4}];
6 O3 {6 o4 e  m. \  Do[f[num[[i, 1]], sym[[j, 1]], num[[i, 2]], sym[[j, 2]],
6 L2 O% t9 l0 u    num[[i, 3]], sym[[j, 3]], num[[i, 4]]], {i, Length[num]}, {j,
. r/ x7 g0 E& `, Q4 A    Length[sym]}]]
1 R7 W+ V) h6 E: ]8 H3 P/ C& [+ i
fs[3, 3, 8, 8]