Mathematica 24点程序！

cjilyy

f[x1_, s1_, x2_, s2_, x3_, s3_, x4_] :=
' ~  `, Q! M" ]- _/ r7 G: C& V Module[{result, i},
  result = {HoldForm[(x1~s1~x2)~s2~(x3~s3~x4)],
    HoldForm[x1~s1~(x2~s2~x3~s3~x4)],
( X2 `; x+ {3 T  Z' ~6 M    HoldForm[x1~s1~x2~s2~(x3~s3~x4)],
( ]; L% o; `9 N/ u' y) X    HoldForm[(x1~s1~x2~s2~x3)~s3~x4],
    HoldForm[x1~s1~(x2~s2~x3)~s3~x4],
$ c' y, x4 e, X5 g, E    HoldForm[(x1~s1~(x2~s2~x3))~s3~x4],
    HoldForm[x1~s1~(x2~s2~(x3~s3~x4))]};
  result = Union[result];
8 |- ^- I; q# `# F  For[i = 1, i <= Length[result], i++,
( b# j& z. ]; I2 F) d* w   If[ReleaseHold[result[[i]]] == 24, Print[result[[i]], "=24"];
     (*Print[TreeForm[result[[i]],DirectedEdges->True]]*);];];]
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fs[x1_, x2_, x3_, x4_] :=
+ A! U5 h1 j7 ]2 `( `9 X Module[{result, s, sym, num, i, j}, Off[Divide::infy];
1 P" M0 b. I# g  Off[Part::partw];
' X9 d% @9 M9 W# z  Off[Divide::indet];
  s = {Plus, Subtract, Times, Divide};
2 F' Y/ B; G0 c1 Z' D) T  sym = Flatten[
/ Z+ Z" M9 w$ W$ C# a    Table[{s[[i]], s[[j]], s[[k]]}, {i, 4}, {j, 4}, {k, 4}], 2];
1 [# S& j8 D* P2 T  V# r  sym = Union[sym];
  num = Permutations[{x1, x2, x3, x4}];
* Z7 ~0 \: S# j6 r" C5 |  Do[f[num[[i, 1]], sym[[j, 1]], num[[i, 2]], sym[[j, 2]],
; R; _, Z1 `/ n% R    num[[i, 3]], sym[[j, 3]], num[[i, 4]]], {i, Length[num]}, {j,
    Length[sym]}]]
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fs[3, 3, 8, 8]