题目地址：点击打开链接
思路：注意每次把队列清空就行
AC代码：
#include <iostream>
#include <queue>
using namespace std;
struct doctor
{
int priority;
int num;
bool operator < (const doctor & x) const
{
if(priority != x.priority)
return priority < x.priority; //最大值优先
else
return num > x.num;//最小值优先
}
};
int main()
{
priority_queue<doctor> pq1,pq2,pq3;
string s;
doctor in,out;
int n,i;
int a,b,k;
while(cin>>n)
{
while(!pq1.empty())//注意是while不是if
pq1.pop();
while(!pq2.empty())
pq2.pop();
while(!pq3.empty())
pq3.pop();
k = 1;
for(i=0; i<n; i++)
{
cin>>s;
if(s == "IN")
{
cin>>a>>b;
in.priority = b;
in.num = k++;
if(a == 1)
{
pq1.push(in);
}
else if(a == 2)
{
pq2.push(in);
}
else
{
pq3.push(in);
}
}
else
{
cin>>a;
if(a == 1)
{
if(pq1.empty())
cout<<"EMPTY"<<endl;
else
{
out = pq1.top();
pq1.pop();
cout<<out.num<<endl;
}
}
if(a == 2)
{
if(pq2.empty())
cout<<"EMPTY"<<endl;
else
{
out = pq2.top();
pq2.pop();
cout<<out.num<<endl;
}
}
if(a == 3)
{
if(pq3.empty())
cout<<"EMPTY"<<endl;
else
{
out = pq3.top();
pq3.pop();
cout<<out.num<<endl;
}
}
}
}
}
return 0;
}
