9*9*8*6+5*3*4*7-1

使用1,2,3,4,5,6,7,8,9共9个数通过加减乘除括号计算4307：
1:((9+8+7)*6*5*2-4)*3-1
2:(((9+8)*7*6+5)*3-4)*2+1
3:(((9+8)*7*6+5)*2-1)*3-4
4:((9+8)*7*6+4)*(5+3-2)-1
5:((9+8)*7*6+4)*(5+1)+2-3
6:((9+8)*7*6+4-1)*3*2+5
7:(((9+8)*7*6+3)*(4+2)+5)*1
8:((9+8)*7*6+3)*(4+2)+5*1
9:((9+8)*7*6+3)*(4+2)*1+5
10:((9+8)*7*6+3)*(4+2*1)+5
11:((9+8)*7*6+3)*(4-1)*2+5
12:((9+8)*7*6+3)*(4*1+2)+5
13:((9+8)*7*6+3*1)*(4+2)+5
14:((9+8)*7*6*2+1)*3+5*4
15:(((9+8)*7*6+1)*2+4)*3+5
16:((9+8)*7*6*1+3)*(4+2)+5
17:((9+8)*7*(5+3-2)+4)*6-1
18:((9+8)*7*(5-2)*3+6)*4-1
19:((9+8)*7*(5+1)+4)*6+2-3
20:((9+8)*7*4*3+6)*(2+1)+5
21:(((9+8)*7*4+2)*(6+3)+5)*1
22:((9+8)*7*4+2)*(6+3)+5*1
23:((9+8)*7*4+2)*(6+3)*1+5
24:((9+8)*7*4+2)*(6+3*1)+5
25:((9+8)*7*4+2)*(6*1+3)+5
26:((9+8)*7*4/2+1)*6*3+5
27:((9+8)*7*4*(2+1)+6)*3+5
28:((9+8)*7*4+2*1)*(6+3)+5
29:((9+8)*7*4*1+2)*(6+3)+5
30:(((9+8)*7*(4+2)+3)*6+5)*1
达到显示上限，共显示30个结果