二分与最大流dining

 暴风式哭泣；

存板子存板子；

终于搞懂了。mmpiu

#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include

using namespace std;

typedef long long ll;
#define INF 0x3fffffff
const int maxn = 100 + 5;
struct edge
{
	int to, cap, rev;
	edge(int a,int b,int c):to(a),cap(b),rev(c){}

};
vector g[maxn*4];
int level[maxn*4];
int iter[maxn*4];
void add_edge(int from, int to, int cap) {
	g[from].push_back(edge(to, cap, g[to].size()));
	g[to].push_back(edge(from, 0, g[from].size()-1));
 }
void bfs(int s) {
	memset(level, -1, sizeof(level));
	queue q;
	level[s] = 0;
	q.push(s);
	while (!q.empty()) {
		int v = q.front();
		q.pop();
		for (int i = 0; i  0 && level[e.to] <0) {
				level[e.to] = level[v] + 1;
				q.push(e.to);
			}
		}
	}
}

int dfs(int v, int t, int f) {
	if (v == t)return f;
	for (int &i = iter[v]; i 0&&level[v] 0) {
				e.cap -= d;
				g[e.to][e.rev].cap += d;
				return d;
			}
		}
	}
	return 0;

}
int max_flow(int s, int t) {
	int flow = 0;
	for (;;) {
		bfs(s);
		if (level[t] <0)return flow;
		memset(iter, 0, sizeof(iter));
		int f;
		while ((f = dfs(s, t, INF)) > 0) {
			flow += f;
		}
	}
}
int N, F, D;
bool likef[maxn][maxn];
bool liked[maxn][maxn];
void solve() {
	int s =0;
	int t = N * 2 + F + D + 1;
	for (int i = 1; i <=F; i++) {
		add_edge(s, N * 2 + i,1);

	}
	for (int i = 1; i <=D; i++) {
		add_edge(N * 2 + F + i, t, 1);
	}
	for (int i = 1; i <=N; i++) {
		add_edge(i, N + i, 1);
		for (int j = 1; j <= F; j++) {
			if (likef[i][j])add_edge(N * 2 + j, i, 1);
		}
		for (int j = 1; j <= D; j++) {
			if (liked[i][j])add_edge(N+i,N * 2+F + j, 1);
		}
	}
	printf("%d\n", max_flow(s, t));
}
int main() {
	while (cin >> N >> F >> D) {
		memset(liked, 0, sizeof(liked));
		memset(likef, 0, sizeof(likef));
		int a, b, x;
		for (int i = 1; i <= N; i++) {
			cin >> a >> b;
			for (int j = 0; j > x;
				likef[i][x] = 1;
			}
			for (int j = 0; j > x;
				liked[i][x] = 1;
			}
		}
		solve();
	}
}