组合问题 ZOJ 1089 Lotto

组合问题

Lotto

 1 #include<iostream>
 2  using namespace std;
 3  int m;
 4  int n = 6;
 5 int b[13];
 6 int c[13];
 7 void combination(int, int);
 8 
 9 int main()
10 {
11     int num;
12     //freopen("test.txt","r", stdin);
13     cin >> num;
14     while (num)
15     {
16         for (int i = 0; i < num; i++)
17         {
18             cin >> c[i];
19         }
20         m = num;
21         combination(0,0);
22         cin >> num;
23         if (num)
24         cout << endl;
25     }
26     
27     return 0;
28 }
29 
30 //计算组合数
31 //m个里面取6个出来
32 void combination(int i, int current)
33 {
34     if (i >= n)
35     {
36         for ( int j = 0; j < n; j++)
37         {
38             if (j == n-1)            
39                 cout << b[j];            
40             else
41             cout << b[j] << " ";    
42         }
43         cout << endl;
44     }
45     else
46     {
47         for (int j = current; j < m-n+i+1; j++)//这里j的上限做了优化，减小不必要的分枝
48         {
49             b[i] = c[j];
50             combination(i+1, j+1);
51         }
52     }
53 }