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poj1151

https://blog.csdn.net/xianpingping/article/details/83032798

#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cstring>
#include<cmath>
#include<stack>
#include<cstdlib>
#include<queue>
#include<set>
#include<string.h>
#include<vector>
#include<deque>
#include<map>
using namespace std;
#define INF 0x3f3f3f3f3f3f3f3f
#define inf 0x3f3f3f3f
#define eps 1e-4
#define bug printf("*********
")
#define debug(x) cout<<#x"=["<<x<<"]" <<endl
typedef long long LL;
typedef long long ll;
const int maxn = 2e2 + 5;
const int mod = 998244353;

struct seg {
    double l,r,h;
    int d;
    seg(){}
    seg(double x1,double x2,double H,int c) : l(x1),r(x2),h(H),d(c){}
    bool operator < (const seg &a) const {
        return h < a.h;
    }
}line[maxn << 2];
double Hash[maxn << 2];
double sum[maxn << 2];
int cnt[maxn << 2];

void init() {
    memset(cnt, 0, sizeof cnt);
    memset(sum, 0, sizeof sum);
}

void pushup(int o,int l,int r) {
    if(cnt[o]) sum[o] = Hash[r + 1] - Hash[l];
    else sum[o] = sum[o << 1] + sum[o << 1 | 1];
}
void update(int o,int l,int r,int ql,int qr,int v) {
    if(ql <= l && qr >= r) {
        cnt[o] += v;
        pushup(o,l,r);
        return;
    }
    int mid = (l + r) >> 1;
    if(ql <= mid) update(o << 1,l,mid,ql,qr,v);
    if(qr > mid) update(o << 1 | 1,mid + 1,r,ql,qr,v);
    pushup(o,l,r);
}
int main()
{
    int n,_  =0;
    while(scanf("%d",&n) && n) {
        init();
        double x1,x2,y1,y2;
        int cnt1 = 0,cnt2 = 0;
        for(int i = 1; i <= n; ++i) {
            scanf("%lf %lf %lf %lf",&x1,&y1,&x2,&y2);
            Hash[++cnt1] = x1;
            Hash[++cnt1] = x2;
            line[++cnt2] = seg(x1,x2,y1,1);
            line[++cnt2] = seg(x1,x2,y2,-1);

        }
        sort(Hash + 1, Hash + cnt1 + 1);
        sort(line + 1, line + cnt2 + 1);
        int k = unique(Hash + 1,Hash + 1 + cnt1) - Hash - 1;
        double ans = 0.0;
        for(int i = 1; i < cnt2; i++) {
            int l = lower_bound(Hash + 1,Hash + 1 + k,line[i].l) - Hash;
            int r = lower_bound(Hash + 1,Hash + 1 + k,line[i].r) - Hash - 1;
            if(l <= r)
                update(1,1,k - 1,l,r,line[i].d);
            ans += sum[1] * (line[i + 1].h  - line[i].h);
        }
        printf("Test case #%d
Total explored area: %.2f

",++_,ans);
    }
}