亚特兰蒂斯

#include<bits/stdc++.h>
using namespace std;

#define int long long

const int N = 1e4+10;

struct Segment{
    double x,y1,y2;
    int d;
    bool operator < (const Segment &t) const{
        return x<t.x;
    }
}seg[N*2];

struct NODE{
    int l,r;
    int cnt;
    double len;
}tr[N*8];

int n;

vector<double> ys;

int find(double y){
    return lower_bound(ys.begin(),ys.end(),y)-ys.begin();
}

void pushup(int u){
    if(tr[u].cnt) tr[u].len=ys[tr[u].r+1]-ys[tr[u].l];
    else if(tr[u].l!=tr[u].r) tr[u].len=tr[u<<1].len+tr[u<<1|1].len;
    else tr[u].len=0;
}

void build(int u,int l,int r){
    if(l==r) tr[u]={l,r,0,0};
    else{
        tr[u]={l,r,0,0};
        int mid=l+r>>1;
        build(u<<1,l,mid);
        build(u<<1|1,mid+1,r);
    }
}

void modify(int u,int l,int r,int d){
    if(l<=tr[u].l && r>=tr[u].r){
        tr[u].cnt+=d;
        pushup(u);
    }
    else{
        int mid=tr[u].l+tr[u].r>>1;
        if(l<=mid) modify(u<<1,l,r,d);
        if(r>mid) modify(u<<1|1,l,r,d);
        pushup(u);
    }
}

signed main(){
    int k=1;
    while(cin>>n,n){
        ys.clear();
        int j=0;
        for(int i=0;i<n;i++){
            double x1,x2,y1,y2;
            cin>>x1>>y1>>x2>>y2;
            seg[j++]={x1,y1,y2,1};
            seg[j++]={x2,y1,y2,-1};
            ys.push_back(y1);
            ys.push_back(y2);
        }
        sort(seg,seg+j);
        
        sort(ys.begin(),ys.end());
        ys.erase(unique(ys.begin(),ys.end()),ys.end());
        
        build(1,0,ys.size()-2);
        
        double res=0;
        
        for(int i=0;i<2*n;i++){
            if(i) res+=(seg[i].x-seg[i-1].x)*tr[1].len;
            modify(1,find(seg[i].y1),find(seg[i].y2)-1,seg[i].d);
        }
        printf("Test case #%d\n",k++);
        printf("Total explored area: %.2lf \n\n",res);
    }
    return 0;
}

标签：int,tr,seg,y1,ys,y2,亚特兰蒂斯
来源： https://www.cnblogs.com/xhy666/p/16389024.html