BZOJ3996 线性代数

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <queue>

#define N 1100010
#define INF 0x3f3f3f3f

using namespace std;

struct edge{
    int x,to,cap;
}E[N<<2];

int n,B[1010][1010],C[N],totE,g[N],S,T,h[N],tot;
queue<int> q;
bool v[N];

#define p E[i].x

void ade(int x,int y,int cap){
    E[++totE]=(edge){y,g[x],cap}; g[x]=totE;
    E[++totE]=(edge){x,g[y],0};   g[y]=totE;
}

bool bfs(){
    memset(v,0,sizeof(v));
    q.push(S); h[S]=1; v[S]=1;
    while(!q.empty()){
        int x=q.front(); q.pop();
        for(int i=g[x];i;i=E[i].to)
            if(E[i].cap&&!v[p]){
                h[p]=h[x]+1;
                q.push(p); v[p]=1;
            }
    }
    return v[T];
}

int dinic(int x,int flow){
    if(x==T||!flow) return flow;
    int f=0;
    for(int i=g[x];i&&flow;i=E[i].to)
        if(h[p]==h[x]+1&&E[i].cap){
            int tmp=dinic(p,min(flow,E[i].cap));
            E[i].cap-=tmp; E[i^1].cap+=tmp;
            f+=tmp; flow-=tmp;
        }
    if(!f) h[x]=-1;
    return f;
}

int main(){
    scanf("%d",&n);
    for(int i=1,j;i<=n;i++)
        for(j=1;j<=n;j++) scanf("%d",&B[i][j]);
    for(int i=1;i<=n;i++) scanf("%d",&C[i]);
    S=n*n+n+1; T=S+1;
    for(int i=1;i<=n;i++) ade(i,T,C[i]);
    int ans=0;
    tot=n;
    for(int i=1;i<=n;i++)
        for(int j=1;j<=n;j++){
            ans+=B[i][j];
            ade(S,++tot,B[i][j]);
            ade(tot,j,INF);
            ade(tot,i,INF);
        }
    while(bfs()) ans-=dinic(S,INF);
    printf("%d\n",ans);
    return 0;
}