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CF1146G Zoning Restrictions

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CF1146G Zoning Restrictions 

网络流

h<=50?

直接都选择最大的,ans=n*h*h

最小割

 

考虑舍弃或者罚款

有一个>x就要罚款?

经典取值限制的模型:切糕割!

每个位置的x+1到额外点tot连接inf边

tot向t连接c边

大概这样:

#include<bits/stdc++.h>
#define reg register int
#define il inline
#define fi first
#define se second
#define mk(a,b) make_pair(a,b)
#define numb (ch^'0')
#define pb push_back
#define solid const auto &
#define enter cout<<endl
#define pii pair<int,int>
using namespace std;
typedef long long ll;
template<class T>il void rd(T &x){
    char ch;x=0;bool fl=false;
    while(!isdigit(ch=getchar()))(ch=='-')&&(fl=true);
    for(x=numb;isdigit(ch=getchar());x=x*10+numb);
    (fl==true)&&(x=-x);
}
template<class T>il void output(T x){if(x/10)output(x/10);putchar(x%10+'0');}
template<class T>il void ot(T x){if(x<0) putchar('-'),x=-x;output(x);putchar(' ');}
template<class T>il void prt(T a[],int st,int nd){for(reg i=st;i<=nd;++i) ot(a[i]);putchar('\n');}

namespace Miracle{
const int N=55;
const int P=N*N;
const int inf=0x3f3f3f3f;
int n,m,h;
int s,t;
struct node{
    int nxt,to;
    int w;
}e[2*(P+P+N*N)];
int hd[P],cnt=1;
void add(int x,int y,int z){
    e[++cnt].nxt=hd[x];
    e[cnt].to=y;e[cnt].w=z;
    hd[x]=cnt;

    e[++cnt].nxt=hd[y];
    e[cnt].to=x;e[cnt].w=0;
    hd[y]=cnt;
}
int d[P];
int q[P],l,r;
int ans;
int dfs(int x,int flow){
    int res=flow;
    if(x==t) return flow;
    for(reg i=hd[x];i&&res;i=e[i].nxt){
        int y=e[i].to;
        if(d[y]==d[x]+1&&e[i].w){
            int k=dfs(y,min(res,e[i].w));
            if(!k) d[y]=0;
            res-=k;
            e[i].w-=k;
            e[i^1].w+=k;
        }   
    }
    return flow-res;
}
bool bfs(){
    memset(d,0,sizeof d);
    l=1,r=0;
    q[++r]=s;
    d[s]=1;
    while(l<=r){
        int x=q[l++];
        for(reg i=hd[x];i;i=e[i].nxt){
            int y=e[i].to;
            if(e[i].w&&!d[y]){
                d[y]=d[x]+1;
                q[++r]=y;
                if(y==t) return true;
            }
        }
    }
    return false;
}
int num(int x,int y){
    return (x-1)*(h+1)+y+1;
}
int main(){
    rd(n);rd(h);rd(m);
    ans=n*h*h;
    s=0;t=num(n,h)+1;
    int tot=t;
    for(reg i=1;i<=n;++i){
        add(s,num(i,0),inf);
        for(reg j=0;j<h;++j){
            add(num(i,j),num(i,j+1),h*h-j*j);
        }
    }
    int l,r,x,c;
    for(reg i=1;i<=m;++i){
        rd(l);rd(r);rd(x);rd(c);
        if(x<h){
            ++tot;
            add(tot,t,c);
            for(reg j=l;j<=r;++j){
                add(num(j,x+1),tot,inf);
            }
        }
    }
    int flow=0;
    while(bfs()){
        while(flow=dfs(s,inf)) ans-=flow;
    }
    ot(ans);
    return 0;
}

}
signed main(){
    Miracle::main();
    return 0;
}

/*
   Author: *Miracle*
*/

 

标签:Restrictions,ch,10,int,void,Zoning,CF1146G,fl,define
来源: https://www.cnblogs.com/Miracevin/p/10857458.html