poj 3680 Intervals 费用流

来源：互联网发布：南京银行怎么样知乎编辑：程序博客网时间：2024/06/05 17:23
#include <stdio.h>#include <iostream>#include <string.h>#include <algorithm>using namespace std;const int MAXN=40000;const int MAXE=20000000;const int inf=1<<30;int head[MAXN],s,t,cnt,ans;int d[MAXN],pre[MAXN];bool vis[MAXN];int q[MAXE];int le[210],ri[210],fee[210];int a[500],b[500];int pos;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 bin(int u){    int l=1,r=pos,m=(l+r)/2;    while(l<=r)    {        m=(l+r)/2;        if(u==b[m]) return m;        else if(u>b[m]) l=m+1;        else if(u<b[m]) r=m-1;    }}int main(){    int n,k;    int cas;    int i,j;    scanf("%d",&cas);    while(cas--)    {        scanf("%d%d",&n,&k);cnt=0;int now=0;for(i=1;i<=n;i++){    scanf("%d%d%d",&le[i],&ri[i],&fee[i]);    a[now++]=le[i];    a[now++]=ri[i];}sort(a,a+now);b[1]=a[0];pos=1;for(i=1;i<now;i++)    if(a[i]!=b[pos])                b[++pos]=a[i];        //for(i=1;i<=pos;i++)printf("%d ",b[i]);        //printf("\n");        s=0;t=pos+1;  //printf("          %d %d\n",s,t);        for(i=0;i<=t;i++)            head[i]=-1;        for(i=1;i<=n;i++)        {            int u,v;            u=bin(le[i]);            v=bin(ri[i]);            //printf("%d %d\n",u,v);            addedge(u,v,-fee[i],1);        }        for(i=0;i<t;i++)            addedge(i,i+1,0,k);        ans=0;        MCMF();        printf("%d\n",-ans);    }    return 0;}
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