油滴扩散

Posted 2021-01-05 lisuier

链接

未完待续
存代码用的

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cmath>
#define db double
using namespace std;
db a[100][3]={0},s,x,y,x1,yy;
db r[1010],ans=0.0;
int vis[1000101]={0},n;
double dis(db xx,db yy,db xx1,db yy1){
    return sqrt((xx-xx1)*(xx-xx1)+(yy-yy1)*(yy-yy1));
}
double minn(int k){
    for(int i=1;i<=n;i++)
        if(i!=k&&vis[i]==1)
            if(r[i]>dis(a[i][1],a[i][2],a[k][1],a[k][2])) return 0;
    double dist=0;
    double ans=min(min(abs(a[k][1]-x),abs(a[k][1]-x1)),min(abs(a[k][2]-y),abs(a[k][2]-yy)));
    for(int i=1;i<=n;i++)
        if(i!=k&&vis[i]==1){
            dist=dis(a[i][1],a[i][2],a[k][1],a[k][2])-r[i];
            ans=min(ans,dist);
        }
    return ans;
}
void dfs(int x,db y){
    if(x==n){
        ans=max(y,ans);
        return;
    }
    for(int i=1;i<=n;i++){
        if(!vis[i]){
            vis[i]=1;
            db lala=minn(i);
            dfs(x+1,y+3.14*lala*lala);
            r[i]=0;
            vis[i]=0;
        }
    }
}
int main(){
    scanf("%d",&n);
    scanf("%lf%lf%lf%lf",&x,&y,&x1,&yy);
    s=abs(x-x1)*abs(y-yy);
    for(int i=1;i<=n;i++)
        scanf("%lf%lf",&a[i][1],&a[i][2]);
    dfs(0,0.0);
    printf("%0.0f",s-ans);
    return 0;
}