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 ;
}