HDU 4337 暴力

#include <bits/stdc++.h>using namespace std;const int maxn = 200;bool g[maxn][maxn], vis[maxn], ans;int res[maxn], n, m, a, b;void DFS(int x, int cnt){if (ans) return;if (cnt == n + 1){if (g[1][res[n]]){cnt--; ans = 1;for (int i = 1; i <= cnt; i++)printf("%d%c", res[i], (i == cnt ? '\n' : ' '));}}else for (int i = 1; i <= n; i++)if (!vis[i] && g[i][x]){vis[i] = 1;res[cnt] = i;DFS(i, cnt + 1);vis[i] = 0;}}int main(int argc, char const *argv[]){while (scanf("%d%d", &n, &m) != EOF){memset(vis, 0, sizeof(vis));memset(g, 0, sizeof(g));while (m--){scanf("%d%d", &a, &b);g[a][b] = g[b][a] = 1;}ans = 0; res[1] = 1, vis[1] = 1;DFS(1, 2);if (!ans) printf("no solution\n");}return 0;}