1391: [Ceoi2008]order

#include <bits/stdc++.h>
using namespace std;
const int INF = 0x3f3f3f3f;

#define rep(i, j, k) for (int i = j; i <= k; ++i)

const int maxn = 1200+100;
const int maxv = 2400+30, maxe = 3000000+10;
struct MaxFlow {
    int edge, head[maxv], to[maxe], next[maxe];
    int cap[maxe];
    MaxFlow() { edge = 0; memset(head, -1, sizeof head); }
    void addedge(int u, int v, int c) {
        to[edge] = v, next[edge] = head[u];
        cap[edge] = c;
        head[u] = edge++;
    }
    void addEdge(int u, int v, int c) {
    //    printf("%d %d %d\n", u, v, c);
        addedge(u, v, c);
        addedge(v, u, 0);
    }

    int s, t;
    int cur[maxv], dis[maxv], que[maxv*maxv/10], front, back;

    bool bfs() {
        que[front=back=0] = s;
        memset(dis, INF, sizeof (int)*(t+10));
        dis[s] = 0;
        while (front <= back) {
            int u = que[front++];
            for (int i=head[u]; i!=-1; i=next[i]) {
                if (cap[i]>0 && dis[to[i]]>dis[u]+1) {
                    dis[to[i]] = dis[u]+1;
                    que[++back] = to[i];
                }
            }
        }
        return dis[t]!=INF;
    }

    int dfs(int u, int a) {
        if (u==t || a==0)
            return a;
        int flow=0, f;
        for (int &i=cur[u], v; i!=-1; i=next[i])
            if (cap[i]>0 && dis[v=to[i]]==dis[u]+1 && (f=dfs(v, min(a, cap[i])))>0) {
                cap[i]-=f, cap[i^1]+=f;
                flow+=f, a-=f;
                if (a==0) break;
            }
        return flow;
    }

    int MF() {
        int ret = 0;
        while (bfs()) {
            memcpy(cur, head, sizeof (int) * (t+10));
            ret += dfs(s, INF);
        }
        return ret;
    }
} mf;

int n, m;

int main() {
    scanf("%d%d", &n, &m);
    int s = 0, t = n+m+1;
    int c, x, sum = 0;
    int p, v;
    for (int i = 1; i <= n; ++i) {
        scanf("%d", &c);
        sum += c;
        mf.addEdge(s, i, c);
        scanf("%d", &x);
        for (int j = 1; j <= x; ++j) {
            scanf("%d %d", &p, &v);
            mf.addEdge(i, n+p, v);
        }
    }
    rep(i, 1, m) {
        scanf("%d", &c);
        mf.addEdge(n+i, t, c);
    }
    mf.s = s, mf.t = t;
    printf("%d\n", sum-mf.MF());

    return 0;
}