哈密顿绕行世界问题---hdu2181(全排列问题)

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=2181

题意很容易理解，dfs就可以了

#include <iostream>
#include <stdio.h>
#include <string.h>
#include <algorithm>
#include <stdlib.h>
#include <queue>
#include <map>
#include <vector>
 
using namespace std;
 
typedef long long LL;
 
#define met(a, b) memset(a, b, sizeof(a))
#define INF 0x3f3f3f3f
#define N 25
 
int G[N][N], A[N], vis[N], t;
 
void dfs(int s, int k)
{
    if(k == )
    {
        if( G[A[]][A[]] )
        {
            A[] = A[];
 
            printf("%d: ", t++);
 
            for(int i=; i<=; i++)
                printf(" %d", A[i]);
 
            printf("\n");
        }
        return;
    }
    for(int i=; i<=; i++)
    {
        if( G[s][i] && !vis[i])
        {
            A[k] = i;
 
            vis[i] = ;
 
            dfs(i, k+);
 
            vis[i] = ;
        }
    }
}
 
int main()
{
    int a, b, c, m;
 
    met(G, );
 
    for(int i=; i<=; i++)
    {
        scanf("%d %d %d", &a, &b, &c);
 
        G[i][a] = G[i][b] = G[i][c] = ;
    }
 
    while(scanf("%d", &m), m)
    {
        t = ;
 
        met(vis, );
 
        met(A, );
 
        A[] = m;
 
        vis[m] = ;
 
        dfs(m, );
    }
    return ;
}