Mathematica 24点程序！

cjilyy

f[x1_, s1_, x2_, s2_, x3_, s3_, x4_] :=
0 w* M1 K2 k% z* v Module[{result, i},
& ^5 J5 l3 F! N3 E  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)],
. u2 x* R9 I2 [# n$ S    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))]};
$ w5 U% i6 z+ }  result = Union[result];
  For[i = 1, i <= Length[result], i++,
, H: q. ]% H' ~5 p   If[ReleaseHold[result[[i]]] == 24, Print[result[[i]], "=24"];
     (*Print[TreeForm[result[[i]],DirectedEdges->True]]*);];];]
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fs[x1_, x2_, x3_, x4_] :=
" n7 F& h  [! g9 d2 E* g+ P; y6 o Module[{result, s, sym, num, i, j}, Off[Divide::infy];
  Off[Part::partw];
$ v" c8 s6 z+ d- u  Off[Divide::indet];
8 R$ ]0 p# F% X) }/ P6 L  s = {Plus, Subtract, Times, Divide};
9 U* V3 e) s. X- F  sym = Flatten[
+ T! j+ I4 Y1 ~" k; e; V    Table[{s[[i]], s[[j]], s[[k]]}, {i, 4}, {j, 4}, {k, 4}], 2];
  sym = Union[sym];
  num = Permutations[{x1, x2, x3, x4}];
4 ?) w. w+ b3 o" M. v# F  Do[f[num[[i, 1]], sym[[j, 1]], num[[i, 2]], sym[[j, 2]],
$ z- u8 Z5 U3 A% n# J# z0 k1 t; U- [    num[[i, 3]], sym[[j, 3]], num[[i, 4]]], {i, Length[num]}, {j,
4 \1 N: z; \6 L" H+ x" r$ }6 Q    Length[sym]}]]
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fs[3, 3, 8, 8]