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)],
% i) o1 C3 E4 q1 F$ U    HoldForm[x1~s1~(x2~s2~x3~s3~x4)],
    HoldForm[x1~s1~x2~s2~(x3~s3~x4)],
' |  Q) u: G9 l    HoldForm[(x1~s1~x2~s2~x3)~s3~x4],
    HoldForm[x1~s1~(x2~s2~x3)~s3~x4],
4 h" v, O, H& T+ c: ^5 m    HoldForm[(x1~s1~(x2~s2~x3))~s3~x4],
    HoldForm[x1~s1~(x2~s2~(x3~s3~x4))]};
  result = Union[result];
7 v, _! H$ F0 F( l" x* o+ H; @5 x  For[i = 1, i <= Length[result], i++,
  b7 b7 F: K" H5 X% ]+ e0 a   If[ReleaseHold[result[[i]]] == 24, Print[result[[i]], "=24"];
, h7 I: R( U- B' `1 ~5 p     (*Print[TreeForm[result[[i]],DirectedEdges->True]]*);];];]
2 z$ ~( o: f6 S: L) H8 E
fs[x1_, x2_, x3_, x4_] :=
Module[{result, s, sym, num, i, j}, Off[Divide::infy];
  Off[Part::partw];
/ {+ R! y; x$ y1 U! o+ g, D  Off[Divide::indet];
  s = {Plus, Subtract, Times, Divide};
  sym = Flatten[
9 s/ u) p* U! v; P( Z1 S9 X/ d, ]- R    Table[{s[[i]], s[[j]], s[[k]]}, {i, 4}, {j, 4}, {k, 4}], 2];
  sym = Union[sym];
6 _# J6 L" Y- k5 u) U/ i  num = Permutations[{x1, x2, x3, x4}];
  Do[f[num[[i, 1]], sym[[j, 1]], num[[i, 2]], sym[[j, 2]],
1 Q" x0 p5 A3 n* b  ~. D% {- X    num[[i, 3]], sym[[j, 3]], num[[i, 4]]], {i, Length[num]}, {j,
9 T. T0 _0 z  C3 h& M2 R    Length[sym]}]]
0 K9 L) y/ ~. F+ d& K- [) f) v
' n/ m) ^$ H1 Sfs[3, 3, 8, 8]