Mathematica 24点程序！

cjilyy

f[x1_, s1_, x2_, s2_, x3_, s3_, x4_] :=
Module[{result, i},
4 Q0 D  `0 ]/ Q0 }2 `( T, ]  result = {HoldForm[(x1~s1~x2)~s2~(x3~s3~x4)],
    HoldForm[x1~s1~(x2~s2~x3~s3~x4)],
5 y7 P2 Y! F/ n: t) E" v; e* f) M2 R; L    HoldForm[x1~s1~x2~s2~(x3~s3~x4)],
! |9 N) ]1 z7 f5 F    HoldForm[(x1~s1~x2~s2~x3)~s3~x4],
4 e5 T; E1 B$ c+ E# O    HoldForm[x1~s1~(x2~s2~x3)~s3~x4],
    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++,
6 Z" {( ]2 m% k   If[ReleaseHold[result[[i]]] == 24, Print[result[[i]], "=24"];
- q/ o5 x$ E: H; ]' D; L     (*Print[TreeForm[result[[i]],DirectedEdges->True]]*);];];]
) }1 M' K( H$ f& k( t' ~6 t
5 T, \# l: m4 ~4 _" lfs[x1_, x2_, x3_, x4_] :=
+ b. z) V0 m; _3 ^ Module[{result, s, sym, num, i, j}, Off[Divide::infy];
* N% V5 V% X$ g  Off[Part::partw];
  Off[Divide::indet];
  s = {Plus, Subtract, Times, Divide};
2 f, R$ R! S0 i! j: Q  sym = Flatten[
$ `( C; O: ?( ~& U& ]9 \& {$ k    Table[{s[[i]], s[[j]], s[[k]]}, {i, 4}, {j, 4}, {k, 4}], 2];
6 K6 j! g: w+ G4 M# d7 j6 Y  sym = Union[sym];
( u: m4 u, g1 V4 w  num = Permutations[{x1, x2, x3, x4}];
, r. x3 h$ s6 r9 ?, W  Do[f[num[[i, 1]], sym[[j, 1]], num[[i, 2]], sym[[j, 2]],
) s1 a6 l2 r) D4 }5 E    num[[i, 3]], sym[[j, 3]], num[[i, 4]]], {i, Length[num]}, {j,
1 H; l6 J9 x' B) L* W    Length[sym]}]]
8 [7 U( e! {4 y: D
fs[3, 3, 8, 8]