问题补充：
1,2,3,4,四个数字,分别用加减乘除计算,得数为24,符号数字只能用一次,而且必须用
答案：
1: (1 + 2 + 3) × 4
2: ((1 + 2) + 3) × 4
3: (1 + (2 + 3)) × 4
4: 1 × 2 × 3 × 4
5: (1 × 2) × 3 × 4
6: (1 × 2 × 3) × 4
7: ((1 × 2) × 3) × 4
8: (1 × (2 × 3)) × 4
9: 1 × (2 × 3) × 4
10: 1 × (2 × 3 × 4)
11: 1 × ((2 × 3) × 4)
12: 1 × (2 × (3 × 4))
13: 1 × 2 ×(3 × 4)
14: (1 × 2) × (3 × 4)
15: 1 × 2 × 4 × 3
16: (1 × 2) × 4 × 3
17: (1 × 2 × 4) × 3
18: ((1 × 2) × 4) × 3
19: (1 × (2 × 4)) × 3
20: 1 × (2 × 4) × 3
21: 1 × (2 × 4 × 3)
22: 1 × ((2 × 4) × 3)
23: 1 × (2 × (4 × 3))
24: 1 × 2 ×(4 × 3)
25: (1 × 2) × (4 × 3)
26: (1 + 3 + 2) × 4
27: ((1 + 3) + 2) × 4
28: (1 + (3 + 2)) × 4
29: (1 + 3) × (2 + 4)
30: 1 × 3 × 2 × 4
31: (1 × 3) × 2 × 4
32: (1 × 3 × 2) × 4
33: ((1 × 3) × 2) × 4
34: (1 × (3 × 2)) × 4
35: 1 × (3 × 2) × 436: 1 × (3 × 2 × 4)37: 1 × ((3 × 2) × 4)38: 1 × (3 × (2 × 4))39: 1 × 3 ×(2 × 4)40: (1 × 3) × (2 × 4)41: (1 + 3) × (4 + 2)42: 1 × 3 × 4 × 243: (1 × 3) × 4 × 244: (1 × 3 × 4) × 245: ((1 × 3) × 4) × 246: (1 × (3 × 4)) × 247: 1 × (3 × 4) × 248: 1 × (3 × 4 × 2)49: 1 × ((3 × 4) × 2)50: 1 × (3 × (4 × 2))51: 1 × 3 ×(4 × 2)52: (1 × 3) × (4 × 2)53: 1 × 4 × 2 × 354: (1 × 4) × 2 × 355: (1 × 4 × 2) × 356: ((1 × 4) × 2) × 357: (1 × (4 × 2)) × 358: 1 × (4 × 2) × 359: 1 × (4 × 2 × 3)60: 1 × ((4 × 2) × 3)61: 1 × (4 × (2 × 3))62: 1 × 4 ×(2 × 3)63: (1 × 4) × (2 × 3)64: 1 × 4 × 3 × 265: (1 × 4) × 3 × 266: (1 × 4 × 3) × 2
