Mathematica 24点程序！

cjilyy

f[x1_, s1_, x2_, s2_, x3_, s3_, x4_] :=
Module[{result, i},
, C2 b2 R4 ^& P: O7 ]) E  result = {HoldForm[(x1~s1~x2)~s2~(x3~s3~x4)],
9 I! p8 k! a1 W' @$ T    HoldForm[x1~s1~(x2~s2~x3~s3~x4)],
    HoldForm[x1~s1~x2~s2~(x3~s3~x4)],
  H* G( F) p3 F) K# C! D    HoldForm[(x1~s1~x2~s2~x3)~s3~x4],
7 u' F# D. K3 |+ P    HoldForm[x1~s1~(x2~s2~x3)~s3~x4],
3 R6 j# \+ t- J: ~2 }    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++,
/ b; f6 i5 R+ u) ~) v' k( l   If[ReleaseHold[result[[i]]] == 24, Print[result[[i]], "=24"];
     (*Print[TreeForm[result[[i]],DirectedEdges->True]]*);];];]

! s. j( [1 O% }fs[x1_, x2_, x3_, x4_] :=
Module[{result, s, sym, num, i, j}, Off[Divide::infy];
  Off[Part::partw];
  Off[Divide::indet];
  s = {Plus, Subtract, Times, Divide};
5 [+ K5 l& u3 U5 p  sym = Flatten[
    Table[{s[[i]], s[[j]], s[[k]]}, {i, 4}, {j, 4}, {k, 4}], 2];
6 u; A+ s* M  E' l  sym = Union[sym];
- ]2 e7 }, l: g" @3 q5 D0 w  num = Permutations[{x1, x2, x3, x4}];
  Do[f[num[[i, 1]], sym[[j, 1]], num[[i, 2]], sym[[j, 2]],
! }  H' i1 C4 |1 o! T+ @: p    num[[i, 3]], sym[[j, 3]], num[[i, 4]]], {i, Length[num]}, {j,
    Length[sym]}]]

9 J) ~8 R, H! a( }! L3 n+ b; Zfs[3, 3, 8, 8]