POJ1149 PIGS

想了好久啊。。。（#－.－）

开始想到m*n个点的构图，明显超时，于是考虑压缩节点个数

我们发现每个猪圈最后被有且只有一个人调整，于是想到对于一个人，连接他能调整的每个猪圈的上一个控制人。（不懂可以开代码 (・(ｪ)・) )

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/**
 * Problem:POJ1149
 * Author:Shun Yao
 * Time:2013.9.13
 * Result:
 * Memo:
 */
  
#include <cstring>
#include <cstdio>
 
#define INF 0x7fffffff
#define MAXT 1111
 
long m, n, s, t, f[MAXT], p2[MAXT], h[MAXT], sum[MAXT];
 
class Edge {
public:
    long v, f;
    Edge *op, *next;
    Edge() {}
    ~Edge() {}
    Edge(long V, long F, Edge *o, Edge *ne) : v(V), f(F), op(o), next(ne) {}
} *g[MAXT], *now[MAXT], *p1[MAXT];
 
void add(long x, long y, long c) {
    g[x] = new Edge(y, c, 0, g[x]);
    g[y] = new Edge(x, 0, g[x], g[y]);
    g[x]->op = g[y];
}
 
long *l, *r, q[MAXT];
void SAP() {
    static char f;
    static Edge *e;
    static long i, ans, ww, w;
    memset(h, -1, sizeof h);
    memset(sum, 0, sizeof sum);
    l = r = q;
    *r++ = t;
    h[t] = 0;
    sum[0] = 1;
    while (l < r) {
        for (e = g[*l]; e; e = e->next)
            if (h[e->v] == -1) {
                ++sum[h[e->v] = h[*l] + 1];
                *r++ = e->v;
            }
        ++l;
    }
    for (i = 0; i <= t; ++i) {
        now[i] = g[i];
        p1[i] = 0;
        p2[i] = -1;
    }
    i = s;
    ans = 0;
    while (h[s] <= t) {
        f = 0;
        for (e = now[i]; e; e = e->next)
            if (e->f > 0 && h[i] == h[e->v] + 1) {
                now[i] = e;
                p1[e->v] = e;
                p2[e->v] = i;
                i = e->v;
                if (i == t) {
                    ww = INF;
                    for (w = t; w != s; w = p2[w])
                        if (ww > p1[w]->f)
                            ww = p1[w]->f;
                    for (w = t; w != s; w = p2[w]) {
                        p1[w]->f -= ww;
                        p1[w]->op->f += ww;
                    }
                    ans += ww;
                    i = s;
                }
                f = 1;
                break;
            }
        if (!f) {
            ww = t + 1;
            for (e = g[i]; e; e = e->next)
                if (e->f > 0 && ww > h[e->v]) {
                    ww = h[e->v];
                    now[i] = e;
                }
            ++sum[ww > t ? ww : ++ww];
            if (!--sum[h[i]])
                break;
            h[i] = ww;
            if (i != s)
                i = p2[i];
        }
    }
    printf("%ld", ans);
}
 
int main() {
    static long i, j, k, A, B;
 
#ifndef ONLINE_JUDGE
    freopen("poj1149.in", "r", stdin);
    freopen("poj1149.out", "w", stdout);
#endif
 
    scanf("%ld%ld", &m, &n);
    s = 0;
    t = n + m + 1;
    for (i = 1; i <= m; ++i) {
        scanf("%ld", &A);
        add(s, i, A);
        f[i] = i;
    }
    for (i = 1; i <= n; ++i) {
        scanf("%ld", &A);
        for (j = 1; j <= A; ++j) {
            scanf("%ld", &k);
            add(f[k], i + m, INF);
            f[k] = i + m;
        }
        scanf("%ld", &B);
        add(i + m, t, B);
    }
    SAP();
 
    fclose(stdin);
    fclose(stdout);
    return 0;
}