uva10330

题目链接请戳 这里

 

解题思路

用最大流。需要注意的只有拆点

 

代码

#include<stdio.h>
#include<string.h>
#include<queue>
#include<algorithm>
#define N 300
#define INF 1e9
using namespace std;

int cap[N][N], flow[N][N], a[N], pre[N];
int n, m, b, d;
queue<int> q;

int EK(int s, int t)
{
    memset(flow, 0, sizeof(flow));
    int f = 0;
    for (;;) {
        memset(a, 0, sizeof(a));
        a[s] = INF;
        q.push(s);
        while (!q.empty()) {
            int u = q.front(); q.pop();
            for (int v = 1; v <= t; v++) if (!a[v] && flow[u][v] < cap[u][v]) {
                pre[v] = u; q.push(v);
                a[v] = min(a[u], cap[u][v] - flow[u][v]);
            }
        }
        if (a[t] == 0) break;
        for (int u = t; u != s; u = pre[u]) {
            flow[pre[u]][u] += a[t];
            flow[u][pre[u]] -= a[t];
        }
        f += a[t];
    }
    return f;
}
    

int main()
{
    while (scanf("%d", &n) != EOF) {
        memset(cap, 0, sizeof(cap));
        for (int i = 1; i <= n; i++) {
            int v;
            scanf("%d", &v);
            cap[i][i+n] = v;
        }
        scanf("%d", &m);
        for (int i = 0; i < m; i++) {
            int x, y, v;
            scanf("%d%d%d", &x, &y, &v);
            cap[x+n][y] = v;
        }
        scanf("%d%d", &b, &d);
        for (int i = 0; i < b; i++) {
            int x;
            scanf("%d", &x);
            cap[0][x] = INF;
        }
        for (int i = 0; i < d; i++) {
            int x;
            scanf("%d", &x);
            cap[x+n][2*n+1] = INF;
        }
        printf("%d\n", EK(0, 2*n+1));
    }
    return 0;
}