cf 434d Nanami's Power Plant 网络流

#include <iostream>
#include <algorithm>
#include <cstdio>
#include <cstring>
using namespace std;
const int maxn=15000;
#define inf 1<<30
int level[maxn],que[maxn];
int head[maxn],lon;
int aa[70],bb[70],cc[70];
int l[70],r[70];
int start[70];
struct edge
{
    int next,to,c;
}e[500000];
void edgeini()
{
    memset(head,-1,sizeof(head));
    lon=-1;
}
void edgemake(int from,int to,int c)
{
    e[++lon].c=c;
    e[lon].to=to;
    e[lon].next=head[from];
    head[from]=lon;
}
void make(int from,int to,int c)
{
    edgemake(from,to,c);
    edgemake(to,from,0);
}

bool makelevel(int s,int t)
{
    memset(level,0,sizeof(level));
    int front=1,end=0;
    que[++end]=s;
    level[s]=1;
    while(front<=end)
    {
        int u=que[front++];
        if(u==t) return true;
        for(int k=head[u];k!=-1;k=e[k].next)
        {
            int v=e[k].to;
            if(!level[v]&&e[k].c)
            {
                que[++end]=v;
                level[v]=level[u]+1;
            }
        }
    }
    return false;
}

int dfs(int now,int t,int maxf)
{
    if(now==t||maxf==0) return maxf;
    int ret=0;
    for(int k=head[now];k!=-1;k=e[k].next)
    {
        int u=e[k].to;
        if(level[u]==level[now]+1&&e[k].c)
        {
            int f=dfs(u,t,min(e[k].c,maxf-ret));
            e[k].c-=f;
            e[k^1].c+=f;
            ret+=f;
            if(ret==maxf) return ret;
        }
    }
    if(ret==0) level[now]=0;
    return ret;
}

int maxflow(int s,int t)
{
    int ret=0;
    while(makelevel(s,t))
    {
        ret+=dfs(s,t,inf);
    }
    return ret;
}
int fun(int p,int x)
{
    return aa[p]*x*x+bb[p]*x+cc[p];
}
int id(int p,int x)
{
    return start[p]+x-l[p];
}
int main()
{
    int n,m;
    int i,j;
    scanf("%d%d",&n,&m);
    edgeini();
    int MAX=-inf;
    int cnt=0;
    for(i=1;i<=n;i++)
        scanf("%d%d%d",&aa[i],&bb[i],&cc[i]);
    for(i=1;i<=n;i++)
    {
        scanf("%d%d",&l[i],&r[i]);
        start[i]=cnt+1;
        cnt=cnt+r[i]-l[i]+2;
        for(j=l[i];j<=r[i];j++)
            MAX=max(MAX,fun(i,j));
    }
    for(i=1;i<=n;i++)
    {
        make(0,start[i],inf);
        for(j=l[i];j<=r[i];j++)
            make(id(i,j),id(i,j+1),MAX-fun(i,j));
        make(id(i,r[i]+1),cnt+1,inf);
    }
    int u,v,d;
    while(m--)
    {
        scanf("%d%d%d",&u,&v,&d);
        for(i=l[u];i<=r[u];i++)
        {
            if(i-d>=l[v]&&i-d<=r[v]+1)
                make(id(u,i),id(v,i-d),inf);
        }
    }
    int ans=maxflow(0,cnt+1);
    printf("%d\n",MAX*n-ans);
    return 0;
}