很裸，左点阵n，右点阵m 问最大匹配是否为n
#include <cstdio>
#include <cstring>
#include <vector>
using namespace std;
vector <int> edge[103];
int pre[303];
bool vis[303];
int n, m;
bool dfs(int u) {
for(int i = 0; i < (int)edge[u].size(); i++) {
int v = edge[u][i];
if(vis[v]) continue;
vis[v] = 1;
if(pre[v] == -1 || dfs(pre[v])) {
pre[v] = u;
return 1;
}
}
return 0;
}
int main() {
int i, cas;
scanf("%d", &cas);
while(cas--) {
scanf("%d%d", &n, &m);
int x, tp;
for(i = 0; i < n; i++)
edge[i].clear();
for(i = 0; i < n; i++) {
scanf("%d", &tp);
while(tp--) {
scanf("%d", &x);
edge[i].push_back(--x);
}
}
memset(pre, -1, sizeof(int)*m);
int cnt = 0;
for(i = 0; i < n; i++) {
memset(vis, 0, sizeof(bool)*m);
if(dfs(i)) cnt++;
if(cnt == n) break;
}
printf("%s\n", cnt==n ? "YES" : "NO"); }
return 0;
}