Stones

优先队列

Sempr他只扔遇到的第奇数块石头，所以是第奇数块石头就需要从优先队列中弹出，改变其所处的位置再放入队列，第偶数块就直接弹出，最后注意找一下最远石块的位置（对于相同位置大小不同的石头就在结构体里面设置一下优先级即可）

Because of the wrong status of the bicycle, Sempr begin to walk east to west every morning and walk back every evening. Walking may cause a little tired, so Sempr always play some games this time. 
There are many stones on the road, when he meet a stone, he will throw it ahead as far as possible if it is the odd stone he meet, or leave it where it was if it is the even stone. Now give you some informations about the stones on the road, you are to tell me the distance from the start point to the farthest stone after Sempr walk by. Please pay attention that if two or more stones stay at the same position, you will meet the larger one(the one with the smallest Di, as described in the Input) first. 

Input

In the first line, there is an Integer T(1<=T<=10), which means the test cases in the input file. Then followed by T test cases. 
For each test case, I will give you an Integer N(0<N<=100,000) in the first line, which means the number of stones on the road. Then followed by N lines and there are two integers Pi(0<=Pi<=100,000) and Di(0<=Di<=1,000) in the line, which means the position of the i-th stone and how far Sempr can throw it. 

Output

Just output one line for one test case, as described in the Description. 

Sample Input

221 52 421 56 6

Sample Output

1112

#include<cstdio>#include<queue>using namespace std;struct list{int pos;int tow;friend bool operator < (struct list a,struct list b){if(a.pos!=b.pos)return a.pos>b.pos;elsereturn a.tow>b.tow;}};int main(){int t;scanf("%d",&t);while(t--){int n,cnt;long long ans;struct list an,tmp;priority_queue <struct list> q;ans=0,cnt=0;scanf("%d",&n);while(n--){scanf("%d%d",&an.pos,&an.tow);q.push(an);}while(!q.empty()){cnt++;if(cnt&1){tmp=q.top();tmp.pos+=tmp.tow;if(tmp.pos>ans)ans=tmp.pos;q.pop();q.push(tmp);}else{if(q.top().pos>ans)ans=q.top().pos;q.pop();}}printf("%lld\n",ans); }return 0;}