POJ1466-Girls and Boys

#include <cstdio>
#include <cctype>
#include <vector>

const int maxv = 1000 + 5;

char s[maxv];

int n;
std::vector<int> G[maxv];
int match[maxv];
bool used[maxv];

void add_edge(int u, int v) {
G[u].push_back(v);
G[v].push_back(u);
}

bool dfs(int v) {
used[v] = true;
for (int i = 0; i < G[v].size(); i++) {
int u = G[v][i], w = match[u];
if (w < 0 || (!used[w] && dfs(w))) {
match[v] = u;
match[u] = v;
return true;
}
}
return false;
}

int Hungarian() {
int res = 0;
memset(match, -1, sizeof(match));
for (int v = 0; v < n; v++) {
if (match[v] < 0) {
memset(used, 0, sizeof(used));
if (dfs(v)) {
res++;
}
}
}
return res;
}

int main() {
while (scanf("%d", &n) == 1) {
getchar();
for (int i = 0; i < n; i++) {
int v, m, u;
scanf("%d: (%d)", &v, &m);
for (int j = 0; j < m; j++) {
scanf("%d", &u);
add_edge(u, v);
}
}
printf("%d\n", n - Hungarian());
for (int i = 0; i < n; i++) {
G[i].clear();
}
}
return 0;
}