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HDU2426:Interesting Housing Problem(还没过,貌似入门题)

#include <iostream>#include <queue>#include <stdio.h>#include <string.h>#include <algorithm>#define inf 1000001using namespace std;struct node{    int x,y,c,w;    int next;} eg[400001];int n,m,K,s,t,tt,head[2005],dis[2005],pre[2005],v[2005];void init(){    memset(head,-1,sizeof(head));    tt=0;    s=0;    t=n+m+1;}void add(int xx,int yy,int cc,int ww){    eg[tt].x=xx;    eg[tt].y=yy;    eg[tt].c=cc;    eg[tt].w=ww;    eg[tt].next=head[xx];    head[xx]=tt++;    eg[tt].x=yy;    eg[tt].y=xx;    eg[tt].c=0;    eg[tt].w=-ww;    eg[tt].next=head[yy];    head[yy]=tt++;}int spfa(int s,int t){    for(int i=s; i<=t; i++)    {        v[i]=0;        dis[i]=inf;        pre[i]=-1;    }    queue<int>q;    q.push(s);    dis[s]=0;    while(!q.empty())    {        int f=q.front();        q.pop();        v[f]=0;        for(int i=head[f]; i!=-1; i=eg[i].next)        {            int w1=eg[i].y;            if(eg[i].c&&dis[w1]>dis[f]+eg[i].w)            {                dis[w1]=dis[f]+eg[i].w;                pre[w1]=i;                if(!v[w1])                {                    v[w1]=1;                    q.push(w1);                }            }        }    }    if(dis[t]==inf)    {        return 0;    }    return 1;}void KM(int s,int t){    int minx,ans=0,V=0;    while(spfa(s,t)==1)    {        minx=inf;        for(int i=pre[t]; i!=-1; i=pre[eg[i].x])        {            minx=min(minx,eg[i].c);        }        for(int i=pre[t]; i!=-1; i=pre[eg[i].x])        {            eg[i].c-=minx;            eg[i+1].c+=minx;        }        V+=minx;        ans+=minx*dis[t];    }    if(V>=n)        printf("%d\n",-ans);    else printf("-1\n");    return ;}int main(){    int xx,yy,zz,T=0;    while(scanf("%d%d%d",&n,&m,&K)!=EOF)    {        init();        while(K--)        {            scanf("%d%d%d",&xx,&yy,&zz);            xx++;            yy++;            if(zz<0)continue;            add(xx,yy+n,1,-zz);        }        for(int i=1; i<=n; i++)        {            add(s,i,1,0);        }        for(int j=n+1; j<=n+m; j++)        {            add(j,t,1,0);        }        printf("Case %d: ",++T);        KM(s,t);    }    return 0;}

 

HDU2426:Interesting Housing Problem(还没过,貌似入门题)