Mathematica 24点程序！

cjilyy

f[x1_, s1_, x2_, s2_, x3_, s3_, x4_] :=
! J8 I4 }# q, c$ t+ w8 W. \ Module[{result, i},
  result = {HoldForm[(x1~s1~x2)~s2~(x3~s3~x4)],
    HoldForm[x1~s1~(x2~s2~x3~s3~x4)],
; R) M: A: c  j    HoldForm[x1~s1~x2~s2~(x3~s3~x4)],
    HoldForm[(x1~s1~x2~s2~x3)~s3~x4],
0 _% J$ p6 |8 |) N0 K. G' }    HoldForm[x1~s1~(x2~s2~x3)~s3~x4],
    HoldForm[(x1~s1~(x2~s2~x3))~s3~x4],
    HoldForm[x1~s1~(x2~s2~(x3~s3~x4))]};
8 u2 _' V2 J6 Q& z  result = Union[result];
; v& N  \: D6 B% i# p- z7 j* t  For[i = 1, i <= Length[result], i++,
2 u8 S1 E; r5 a9 P$ Q( O   If[ReleaseHold[result[[i]]] == 24, Print[result[[i]], "=24"];
     (*Print[TreeForm[result[[i]],DirectedEdges->True]]*);];];]

fs[x1_, x2_, x3_, x4_] :=
Module[{result, s, sym, num, i, j}, Off[Divide::infy];
  R# ]) d) K/ ?6 @4 L3 `! a  Off[Part::partw];
  Off[Divide::indet];
  s = {Plus, Subtract, Times, Divide};
  sym = Flatten[
7 b6 D6 x1 l  Y; M+ z4 `    Table[{s[[i]], s[[j]], s[[k]]}, {i, 4}, {j, 4}, {k, 4}], 2];
  sym = Union[sym];
  num = Permutations[{x1, x2, x3, x4}];
  Do[f[num[[i, 1]], sym[[j, 1]], num[[i, 2]], sym[[j, 2]],
4 ~( B8 N8 Z& b9 W: C9 K( ]  C    num[[i, 3]], sym[[j, 3]], num[[i, 4]]], {i, Length[num]}, {j,
& l3 g  d) E" ~4 k) _    Length[sym]}]]

fs[3, 3, 8, 8]