hdu 1029 Ignatius and the Princess IV

Ignatius and the Princess IV

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32767 K (Java/Others)
Total Submission(s): 34652    Accepted Submission(s): 15125

Problem Description

"OK, you are not too bad, em... But you can never pass the next test." feng5166 says.

"I will tell you an odd number N, and then N integers. There will be a special integer among them, you have to tell me which integer is the special one after I tell you all the integers." feng5166 says.

"But what is the characteristic of the special integer?" Ignatius asks.

"The integer will appear at least (N+1)/2 times. If you can't find the right integer, I will kill the Princess, and you will be my dinner, too. Hahahaha....." feng5166 says.

Can you find the special integer for Ignatius?

 

Input

The input contains several test cases. Each test case contains two lines. The first line consists of an odd integer N(1<=N<=999999) which indicate the number of the integers feng5166 will tell our hero. The second line contains the N integers. The input is terminated by the end of file.

 

Output

For each test case, you have to output only one line which contains the special number you have found.

 

Sample Input

5 1 3 2 3 3 11 1 1 1 1 1 5 5 5 5 5 5 7 1 1 1 1 1 1 1

 

Sample Output

3 5 1

 

这个题目可以很容易的看出来，在一个序列中如果去掉2个不同的元素，
那么序列中的多元素还是多元素，

所以我们只要加一个num计数器   和一个flag来保存那个元素 
我们遇到一个与flag相同的num就加1   不同就减1
如果num等于0了   那就更新flag


这个题目要注意：
不能使用数组保存  不然会超内存
不能使用cin  cout   不然会超时间

#include <stdlib.h>
#include <iostream>
#include <cstdio>
#include <cstring>
#include <vector>
#include <algorithm>
using namespace std;
int main() {
   int n;
   while(~scanf("%d",&n))
   {
       int num=0,flag,x;
       for(int i=0;i<n;i++)
      {
               scanf("%d",&x);
               if(num==0)
               {
                   num++;
                   flag=x;
               }
               else if(flag==x)
               {
                   num++;
               }
               else
               {
                   num--;
               }
      }
      printf("%d
",flag);
   }
    return 0;
}