二分图最大匹配

#include <bits/stdc++.h>

using namespace std;

#define re register
#define rep(i, a, b) for (re int i = a; i <= b; ++i)
#define repd(i, a, b) for (re int i = a; i >= b; --i)
#define maxx(a, b) a = max(a, b);
#define minn(a, b) a = min(a, b);
#define LL long long
#define inf (1 << 30)

inline int read() {
    int w = 0, f = 1; char c = getchar();
    while (!isdigit(c)) f = c == '-' ? -1 : f, c = getchar();
    while (isdigit(c)) w = (w << 3) + (w << 1) + (c ^ '0'), c = getchar();
    return w * f;
}

const int maxn = 1000 + 5;

int e[maxn << 1][maxn << 1], v[maxn], lk[maxn];
int n, m, E;

bool find(int u) {
    rep(i, 1, m)
        if (!v[i] && e[u][i+n]) {
            v[i] = 1;
            if (!lk[i] || find(lk[i])) {
                lk[i] = u;
                return true;
            }
        }
    return false;
}

int main() {
    n = read(), m = read(), E = read();

    rep(i, 1, E) {
        register int u = read(), v = read();
        e[u][v+n] = e[v+n][u] = 1;
    }

    int cnt = 0;
    rep(i, 1, n) {
        memset(v, 0, sizeof(v)); // 如果题目要求比较高，不要用这句话，改为时间戳判断。
        if (find(i)) cnt++;
    }

    printf("%d", cnt);
    return 0;
}