hdu 3395 Special Fish 带权匹配 费用流

 

#include <cstdio>
#include <iostream>
#include <cstring>
using namespace std;
const int N=1300;
const int MAXE=200000;
const int inf=1<<30;
int head[N],s,t,cnt,n,ans;
int d[N],pre[N];
bool vis[N];
int q[MAXE];
int val[110];
char str[110];
struct Edge
{
    int u,v,c,w,next;
}edge[MAXE];

void addedge(int u,int v,int w,int c)
{
    edge[cnt].u=u;
    edge[cnt].v=v;
    edge[cnt].w=w;
    edge[cnt].c=c;
    edge[cnt].next=head[u];
    head[u]=cnt++;
    edge[cnt].v=u;
    edge[cnt].u=v;
    edge[cnt].w=-w;
    edge[cnt].c=0;
    edge[cnt].next=head[v];
    head[v]=cnt++;
}

int SPFA()
{
    int l,r;
    memset(pre,-1,sizeof(pre));
    memset(vis,0,sizeof(vis));
    for(int i=0;i<=t;i++) d[i]=inf;
    d[s]=0;
    l=0;r=0;
    q[r++]=s;
    vis[s]=1;
    while(l<r)
    {
        int u=q[l++];
        vis[u]=0;
        for(int j=head[u];j!=-1;j=edge[j].next)
        {
            int v=edge[j].v;
            if(edge[j].c>0&&d[u]+edge[j].w<d[v])
            {
                d[v]=d[u]+edge[j].w;
                pre[v]=j;
                if(!vis[v])
                {
                    vis[v]=1;
                    q[r++]=v;
                }
            }
        }
    }
    if(d[t]==inf)
        return 0;
    return 1;
}

void MCMF()
{
    int flow=0;
    while(SPFA())
    {
        int u=t;
        int mini=inf;
        while(u!=s)
        {
            if(edge[pre[u]].c<mini)
                mini=edge[pre[u]].c;
                u=edge[pre[u]].u;
        }
        flow+=mini;
        u=t;
        ans+=d[t]*mini;
        while(u!=s)
        {
            edge[pre[u]].c-=mini;
            edge[pre[u]^1].c+=mini;
            u=edge[pre[u]].u;
        }
    }
}

int main()
{
    while(1)
    {
        int i,j;
        scanf("%d",&n);
        if(n==0) break;
        cnt=0;
        s=0,t=n*2+2;
        memset(head,-1,sizeof(head));
        for(i=1;i<=n;i++) {scanf("%d",&val[i]);addedge(s,i,0,1);addedge(i,2*n+1,0,1);addedge(i+n,t,0,1);}
        addedge(2*n+1,t,0,inf);
        for(i=1;i<=n;i++)
        {
            scanf("%s",str+1);
            int len=strlen(str+1);
            for(j=1;j<=len;j++)
                if(str[j]=='1')
                    addedge(i,j+n,-(val[i]^val[j]),1);
        }
        ans=0;
        MCMF();
        printf("%d\n",-ans);
    }
    return 0;
}