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)],
( j4 E& `; N+ ^* P3 ?  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],
9 v4 P- q! l: n    HoldForm[(x1~s1~(x2~s2~x3))~s3~x4],
    HoldForm[x1~s1~(x2~s2~(x3~s3~x4))]};
  result = Union[result];
  For[i = 1, i <= Length[result], i++,
   If[ReleaseHold[result[[i]]] == 24, Print[result[[i]], "=24"];
4 X; |! }$ y% o1 e6 L  A" O     (*Print[TreeForm[result[[i]],DirectedEdges->True]]*);];];]
; v% d. U- f5 M/ q% p7 b
fs[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};
  sym = Flatten[
, a/ k: F) p" ]4 U. Q! A: G+ O    Table[{s[[i]], s[[j]], s[[k]]}, {i, 4}, {j, 4}, {k, 4}], 2];
  q. j, |# A" _( Q  sym = Union[sym];
  num = Permutations[{x1, x2, x3, x4}];
  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]}]]

$ u' q% I# j0 V$ j% Y; Jfs[3, 3, 8, 8]