【优先队列】POJ3614-Sunscreen

参考：❀

#include<iostream>
#include<cstdio>
#include<queue>
#include<algorithm>
using namespace std;
const int MAXN=2500+50;
struct rec
{
    int a,b;
    bool operator < (const rec& x) const
    {
        return a<x.a;
    }
};

rec cow[MAXN],sunscreen[MAXN];
int C,L,ans=0;

int main()
{
    scanf("%d%d",&C,&L);
    for (int i=0;i<C;i++) scanf("%d%d",&cow[i].a,&cow[i].b); //a:min b:max
    for (int i=0;i<L;i++) scanf("%d%d",&sunscreen[i].a,&sunscreen[i].b);//a:effect b:num
    priority_queue< int,vector<int>,greater<int> > pque;
    sort(cow,cow+C);
    sort(sunscreen,sunscreen+L);
    int j=0;
    for (int i=0;i<L;i++)
    {
        while (j<C && cow[j].a<=sunscreen[i].a)
        {
            pque.push(cow[j].b);
            j++;
        }
        while (!pque.empty() && sunscreen[i].b)//莫忘队列为空时也不执行 
        {
            int temp=pque.top();
            pque.pop();
            if (temp<sunscreen[i].a) continue;
            sunscreen[i].b--;
            ans++;
        }
    }
    cout<<ans<<endl;
    return 0;
}