HDOJ1896(Stones)

Stones

Time Limit: 5000/3000 MS (Java/Others)    Memory Limit: 65535/32768 K (Java/Others)
Total Submission(s): 147    Accepted Submission(s): 66

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

2

2

1 5

2 4

2

1 5

6 6

 

Sample Output

11

12

 

//1279448 2009-04-17 12:42:04 Accepted 1896 218MS 1720K 956 B C++ Xredman 
#include <iostream>
#include <queue>
using namespace std;

const int N = 100002;

typedef struct Node
{
    int curr;//当前位置
    int dis;//可以投石的距离
    friend bool operator < (Node a, Node b)
    {
        if(a.curr != b.curr)
            return a.curr > b.curr;//按位置从小到大排序
        else
            return a.dis > b.dis;//按所投距离从小到大排序
    }
}Node;


int main()
{
    int T, n, i, result;
    int curr;
    bool flag;//用于标记是偶数块石子，还是奇数块石子
    Node stone;
    while(cin>>T)
        while(T-- && cin>>n)
        {
            priority_queue<Node> Q;
            for(i = 0; i < n; i++)
            {
                scanf("%d%d", &stone.curr, &stone.dis);
                Q.push(stone);
            }
            curr = -1;
            flag = true;
            while(!Q.empty())
            {
                stone = Q.top();
                Q.pop();
                if(curr == stone.curr)
                    continue;//若有n块石子在相同位置，则选取投石距离最小的一块
                if(flag)
                {
                    
                    stone.curr += stone.dis;
                    Q.push(stone);
                    flag = false;
                }
                else
                    flag = true;
                result = stone.curr;
            }
            cout<<result<<endl;
        }
    return 0;
}