bzoj 1001 狼抓兔子

裸的最小割，直接上模板就行了

#define MAXN 1000010UL
#include <cstdio>
#include <cstring>
#define INF 1e9

using namespace std;

int n, m, t, hd, tl, S, T, d[MAXN], sn[MAXN], q[MAXN];

struct Edge {
    int hou, nt, zhi;
}sg[6000010];

int Cal(int i, int j) {
    return (i-1)*m+j;
}

void Add(int x, int y, int z) {
    sg[t] = (Edge){y, d[x], z}, d[x] = t ++;
    sg[t] = (Edge){x, d[y], z}, d[y] = t ++;
    return;
}

bool Bfs() {
    memset(sn, 0, sizeof(sn[0])*(T+1));
    hd = tl = 0;
    q[++ tl] = S, sn[S] = 1;
    while(hd<tl) {
        int op = q[++ hd];
        for(int i = d[op] ; i != -1 ; i = sg[i].nt) {
            if(sg[i].zhi&&(!sn[sg[i].hou])) {
                sn[sg[i].hou] = sn[op]+1;
                q[++ tl] = sg[i].hou;
                if(sg[i].hou==T) return true;
            }
        }
    }
    return false;
}

int MIN(int A, int B) { return A<B?A:B; }

int Dfs(int op, int fw) {
    if(op==T) return fw;
    int tmp = fw, k;
    for(int i = d[op] ; i != -1 ; i = sg[i].nt) {
        if(sg[i].zhi&&tmp&&sn[sg[i].hou]==sn[op]+1) {
            k = Dfs(sg[i].hou, MIN(sg[i].zhi, tmp));
            if(!k) {
                sn[sg[i].hou] = 0;
                continue;
            }
            tmp -= k;
            sg[i].zhi -= k, sg[i^1].zhi += k;
        }
    }
    return fw-tmp;
}

int main() {
    memset(d, -1, sizeof(d));
    int x;
    scanf("%d%d", &n, &m);
    for(int i = 1 ; i <= n ; ++ i) {
        for(int j = 1 ; j < m ; ++ j) {
            scanf("%d", &x);
            Add(Cal(i, j), Cal(i, j+1), x);
        }
    }
    for(int i = 1 ; i < n ; ++ i) {
        for(int j = 1 ; j <= m ; ++ j) {
            scanf("%d", &x);
            Add(Cal(i, j), Cal(i+1, j), x);
        }
    }
    for(int i = 1 ; i < n ; ++ i) {
        for(int j = 1 ; j < m ; ++ j) {
            scanf("%d", &x);
            Add(Cal(i, j), Cal(i+1, j+1), x);
        }
    }
    S = Cal(1, 1), T = Cal(n, m);
    int fw = 0, p;
    while(Bfs()) while(p = Dfs(S, INF)) fw += p;
    printf("%d", fw);
    return 0;
}