hdu 2181 哈密顿绕行世界问题 (dfs)

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

简单深搜，路径存储。

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <queue>
using namespace std;
int map[25][25];
int vis[25];
int path[25];
int k;
int m;
void dfs(int id, int num) {
    int i, j;
    if(num == 21 && path[num] == m) {
        printf("%d: ", k++);
        for(i = 1; i <= 21; i++) {
            printf(" %d", path[i]);
        }
        printf("\n");
    }
    for(i = 1; i <= 20; i++) {
        if(map[id][i] == 1 && vis[i] == 0) {
            vis[i] = 1;
            path[num + 1] = i;
            dfs(i, num + 1);
            vis[i] = 0;
        }
    }
}
int main() {
    int i, j;
    memset(map, 0, sizeof(map));
    memset(vis, 0, sizeof(vis));
    k = 1;
    for(i = 1; i <= 20; i++) {
        for(j = 1; j <= 3; j++) {
            int t;
            scanf("%d", &t);
            map[i][t] = 1;
            map[t][i] = 1;
        }
    }
    while(~scanf("%d", &m) && m) {
        path[1] = m;
        dfs(m, 1);
    }
    return 0;
}