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)],
    HoldForm[x1~s1~(x2~s2~x3~s3~x4)],
    HoldForm[x1~s1~x2~s2~(x3~s3~x4)],
# @0 s& b2 n$ f% i8 ^    HoldForm[(x1~s1~x2~s2~x3)~s3~x4],
& k& x+ U3 ?. ]. c4 a. ~    HoldForm[x1~s1~(x2~s2~x3)~s3~x4],
    HoldForm[(x1~s1~(x2~s2~x3))~s3~x4],
    HoldForm[x1~s1~(x2~s2~(x3~s3~x4))]};
4 }, `; g( i' \) n. i3 y  result = Union[result];
) ^1 g, Z" J8 U2 w6 O+ S3 A  For[i = 1, i <= Length[result], i++,
   If[ReleaseHold[result[[i]]] == 24, Print[result[[i]], "=24"];
1 w* t4 U0 o+ O4 D, H2 U9 L     (*Print[TreeForm[result[[i]],DirectedEdges->True]]*);];];]

fs[x1_, x2_, x3_, x4_] :=
$ N: K% v- v5 t$ I0 R: ]* C Module[{result, s, sym, num, i, j}, Off[Divide::infy];
  Off[Part::partw];
+ z) ^2 I0 k, {3 t. u  Off[Divide::indet];
% i$ H8 n, S; k+ g& @3 r) \  s = {Plus, Subtract, Times, Divide};
  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}];
# i( F" o' W) Z$ c% t6 {% U  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]}]]
* q% {/ {! _4 H0 ~
* e( j8 a/ h% v, V' }5 D- Vfs[3, 3, 8, 8]