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)],
    HoldForm[(x1~s1~x2~s2~x3)~s3~x4],
  d$ j+ F& l! p; m+ s; `; {. 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))]};
9 H: `9 f0 x$ K4 g- o  result = Union[result];
  For[i = 1, i <= Length[result], i++,
   If[ReleaseHold[result[[i]]] == 24, Print[result[[i]], "=24"];
     (*Print[TreeForm[result[[i]],DirectedEdges->True]]*);];];]
$ S$ F7 [% I8 O: T* V& B- U
9 n( R* J) u! s9 Mfs[x1_, x2_, x3_, x4_] :=
2 F5 c2 Q* N# g. q8 g8 f( R7 Q& [ Module[{result, s, sym, num, i, j}, Off[Divide::infy];
2 {! x+ |2 C" q. k  Off[Part::partw];
  Off[Divide::indet];
& P1 z' `8 A. Z3 P& l0 ~( K3 @  s = {Plus, Subtract, Times, Divide};
- X6 m7 P; A7 A/ t  sym = Flatten[
9 Q% J5 q2 k1 p/ i# M- ^    Table[{s[[i]], s[[j]], s[[k]]}, {i, 4}, {j, 4}, {k, 4}], 2];
. w$ z" f2 {7 h& Q8 }5 Q  sym = Union[sym];
- k. ]7 g4 j9 u  Z0 x  num = Permutations[{x1, x2, x3, x4}];
. C: V  y% U8 r7 X: F  Do[f[num[[i, 1]], sym[[j, 1]], num[[i, 2]], sym[[j, 2]],
5 z, K1 ]1 `5 E0 x    num[[i, 3]], sym[[j, 3]], num[[i, 4]]], {i, Length[num]}, {j,
* K1 S5 \9 }+ I    Length[sym]}]]

9 S1 l% w( O! t$ d! Ffs[3, 3, 8, 8]