HDU-1896-Stones

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=1896

Stones

Problem Description

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

 

题目分析：一条直线从左到右有n个石头，pi代表石头所在的位置，di表示能够扔出去多远，遇到的石头是第奇数个，就扔出去，如果是偶数个就不扔，求出最远距离。（你会遇到原来扔过的石头）。

#include<iostream>#include<queue>using namespace std;struct node{int pos;int dis;bool operator<(const node t)const{//从大到小排序. if(pos!=t.pos)return t.pos<pos;return t.dis<dis;}};int main(){int n;cin>>n;while(n--){int m;cin>>m;priority_queue<node> q;    node now;    int i;    for(i=0;i<m;i++)    {    scanf("%d%d",&now.pos,&now.dis);    q.push(now);}bool flag=true;//切换奇偶 while(!q.empty()){now=q.top();q.pop();if(flag==true){flag=false;now.pos+=now.dis;q.push(now);}elseflag=true;//偶数个不处理 }cout<<now.pos<<endl;}return 0;}