hdu 1716 dfs写法

基础dfs，输出要求还真是多，可以用stl做，不过自己还是手写了一下。

  1 #include <algorithm>
  2 #include <iostream>
  3 #include <cstring>
  4 using namespace std;
  5 
  6 const int N = 4;
  7 const int M = 24;
  8 const int K = 1000;
  9 int index;
 10 int num[N];
 11 bool visit[N];
 12 int tmp[N];
 13 int ans[M + 1];
 14 int cnt;
 15 
 16 struct Node 
 17 {
 18     int num[N];
 19 } node[K];
 20 
 21 void dfs( int i )
 22 {
 23     if ( i == 4 )
 24     {
 25         int sum = 0;
 26         for ( int j = 0; j < 4; j++ )
 27         {
 28             sum = sum * 10 + tmp[j];
 29         }
 30         ans[cnt++] = sum;
 31         return ;
 32     }
 33     for ( int k = 0; k < 4; k++ )
 34     {
 35         if ( !visit[k] )
 36         {
 37             visit[k] = 1;
 38             tmp[i] = num[k];
 39             dfs( i + 1 );
 40             visit[k] = 0;            
 41         }
 42     }
 43 }
 44 
 45 void solve( int p )
 46 {
 47     for ( int i = 0; i < N; i++ )
 48     {
 49         num[i] = node[p].num[i];
 50     }
 51     cnt = 0;
 52     memset( visit, 0, sizeof(visit) );    
 53     dfs(0);
 54     sort( ans, ans + cnt );
 55     for ( int i = 0; i < cnt - 1; i++ )
 56     {
 57         if ( ans[i] == ans[i + 1] )
 58         {
 59             for ( int j = i; j < cnt - 1; j++ )
 60             {
 61                 ans[j] = ans[j + 1];
 62             }
 63             cnt--;
 64             i--;
 65         }
 66     }
 67     ans[cnt++] = 9999999;
 68     int i = 0;
 69     while ( ans[i] < 1000 ) i++;
 70     int sp = ans[i] / 1000;    
 71     for ( ; i < cnt - 1; i++ )
 72     {
 73         cout << ans[i];
 74         if ( ans[i + 1] / 1000 == sp ) 
 75         {
 76             cout << ' ';
 77         }
 78         else 
 79         {
 80             cout << endl;
 81             sp = ans[i + 1] / 1000;
 82         }
 83     }
 84 }
 85 
 86 int main()
 87 {
 88     index = 0;
 89     while ( 1 )
 90     {
 91         int s = 0;
 92         for ( int i = 0; i < 4; i++ ) 
 93         {
 94             cin >> node[index].num[i];
 95             s += node[index].num[i];
 96         }
 97         if ( !s ) break;
 98         index++;
 99     }
100     for ( int i = 0; i < index; i++ )
101     {
102         solve(i);
103         if ( i != index - 1 ) cout << endl;
104     }
105     return 0;
106 }
posted @ 2015-04-20 17:21  hxy_has_been_used  阅读(197)  评论(0)  编辑  收藏  举报