优先队列基础

HDU1873

题目链接

题解：裸题，注意队列要清空，记下优先队列模板；

Code：

#include <cstdio>
#include <queue>
using namespace std;
struct p
{
    int no;
    int level;
    friend bool operator <(p a,p b)
    {
        if(a.level==b.level)return a.no>b.no;
        return a.level<b.level;
    }
};
priority_queue<struct p> xq[5];
int main()
{
    int n,a,b;
    char s[100];
    while(scanf("%d",&n)!=EOF)
    {
        int k=0;
        for(int i=1;i<=3;i++)
        while(!xq[i].empty())xq[i].pop();//****
        for(int i=1; i<=n; i++)
        {
            scanf(" %s %d",s,&a);
            if(s[0]=='I')
            {
                scanf("%d",&b);
                p x;
                x.level=b;
                x.no=(++k);
                xq[a].push(x);
            }
            else if(s[0]=='O')
            {
                if(xq[a].empty())
                {
                    printf("EMPTY\n");
                }
                else
                {
                    printf("%d\n",(xq[a].top()).no);
                    xq[a].pop();
                }
            }
        }

    }
    return 0;
}