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先抄个模板

EK：

const int MAXN = 430;
const int MAX_INT = (1 << 30);
 
struct Edge{
    int v, nxt, w;
};
 
struct Node{
    int v, id;
};
 
int n, m, ecnt;
bool vis[MAXN];
int head[MAXN];
Node pre[MAXN];
Edge edge[MAXN];
 
void init(){
    ecnt = 0;
    memset(edge, 0, sizeof(edge));
    memset(head, -1, sizeof(head));
}
 
void addEdge(int u, int v, int w){
    edge[ecnt].v = v;
    edge[ecnt].w = w;
    edge[ecnt].nxt = head[u];
    head[u] = ecnt++;
}
 
bool bfs(int s, int t){
    queue <int> que;
    memset(vis, 0, sizeof(vis));
    memset(pre, -1, sizeof(pre));
    pre[s].v = s;
    vis[s] = true;
    que.push(s);
    while(!que.empty()){
        int u = que.front();
        que.pop();
        for(int i = head[u]; i + 1; i = edge[i].nxt){
            int v = edge[i].v;
            if(!vis[v] && edge[i].w){
                pre[v].v = u;
                pre[v].id = i;
                vis[v] = true;
                if(v == t) return true;
                que.push(v);
            }
        }
    }
    return false;
}
 
int EK(int s, int t){
    int ans = 0;
    while(bfs(s, t)){
        int mi = MAX_INT;
        for(int i = t; i != s; i = pre[i].v){
            mi = min(mi, edge[pre[i].id].w);
        }
        for(int i = t; i != s; i = pre[i].v){
            edge[pre[i].id].w -= mi;
            edge[pre[i].id ^ 1].w += mi;
        }
        ans += mi;
    }
    return ans;
}
 
// 加边
addEdge(u, v, w);
addEdge(v, u, 0);
// 调用
int ans = EK(s, t);