Mathematica 24点程序！

cjilyy

f[x1_, s1_, x2_, s2_, x3_, s3_, x4_] :=
; @  d* T/ p4 q+ h) g" L' W9 w Module[{result, i},
  result = {HoldForm[(x1~s1~x2)~s2~(x3~s3~x4)],
' G2 K$ @+ |$ u- L% u    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],
9 a) A) A6 J/ s  C- a* o% W    HoldForm[(x1~s1~(x2~s2~x3))~s3~x4],
' B' u& ]7 G. s8 {; C  K) p  I& B    HoldForm[x1~s1~(x2~s2~(x3~s3~x4))]};
  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]]*);];];]
2 ~+ y1 S1 ~- e( X+ ^
5 v# h# \) K' J$ p5 g0 M0 \fs[x1_, x2_, x3_, x4_] :=
Module[{result, s, sym, num, i, j}, Off[Divide::infy];
  Off[Part::partw];
" Y8 j$ K( p9 Y. r* X5 V9 J  Off[Divide::indet];
% h* ]" L  ]) J/ s# Y0 k7 v  s = {Plus, Subtract, Times, Divide};
: F1 X& c6 G2 R6 I; B  sym = Flatten[
    Table[{s[[i]], s[[j]], s[[k]]}, {i, 4}, {j, 4}, {k, 4}], 2];
  sym = Union[sym];
  num = Permutations[{x1, x2, x3, x4}];
) V( d1 G- e$ Q5 [$ ^; V- T3 d  Do[f[num[[i, 1]], sym[[j, 1]], num[[i, 2]], sym[[j, 2]],
* U1 k0 x/ A+ O% y* P5 n- {4 s$ ^; u    num[[i, 3]], sym[[j, 3]], num[[i, 4]]], {i, Length[num]}, {j,
    Length[sym]}]]

fs[3, 3, 8, 8]