最高的奖励 优先队列

#include <iostream>
#include <cstdio>
#include <queue>
#include <map>
#include <algorithm>
using namespace std;
int n;
struct assign
{
    int time,award;
    friend bool operator <(assign a,assign b)
    {
        return a.award>b.award;
    }
}as[50000];
int cmp(assign a,assign b)
{
    return a.time<b.time;
}
int main()
{
    int n;
    long long sum=0;
    priority_queue <assign>q;
    scanf("%d",&n);
    for(int i=0;i<n;i++)
    {
        scanf("%d %d",&as[i].time,&as[i].award);
    }
    sort(as,as+n,cmp);
    for(int i=0;i<n;i++)
    {
        q.push(as[i]);
        sum+=as[i].award;
        if(i<n-1&&as[i+1].time!=as[i].time)
        {
            while(q.size()>as[i].time)
            {
                sum-=q.top().award;
                q.pop();
            }
        }
    }
            while(q.size()>as[n-1].time)
            {
                sum-=q.top().award;
                q.pop();
            }
            printf("%lld",sum);
}