HDU 1896 优先队列用法

#include <bits/stdc++.h>

using namespace std;

struct node{
    int pos,dis;
    friend bool operator<(node a,node b){
        if(a.pos!=b.pos)
        return a.pos>b.pos;//最小值优先
        else return a.dis>b.dis;
    }
};
int main(){
    int t;
    while(cin>>t){
        while(t--){
            int n;
            cin>>n;
            
            priority_queue<node>q;
            
            node a,b;
            
            for(int i=0;i<n;i++){
                int c,d;
                cin>>c>>d;
                a.pos=c;
                a.dis=d;
                q.push(a);
            }
            
            int z=0;
            int sum=0;
            
            while(!q.empty()){
                z++;
                a=q.top();
                sum=a.pos;
                if(z%2==0){
                    q.pop();
                }
                else{
                    b.pos=a.pos+a.dis;
                    b.dis=a.dis;
                    q.pop();
                    q.push(b);
                }
            }
            cout<<sum<<endl;
        }
    }
    return 0;
}