HDU2095find your present (2)

find your present (2)

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 22130    Accepted Submission(s): 8755

Problem Description

In the new year party, everybody will get a "special present".Now it's your turn to get your special present, a lot of presents now putting on the desk, and only one of them will be yours.Each present has a card number on it, and your present's card number will be the one that different from all the others, and you can assume that only one number appear odd times.For example, there are 5 present, and their card numbers are 1, 2, 3, 2, 1.so your present will be the one with the card number of 3, because 3 is the number that different from all the others.

 

Input

The input file will consist of several cases. 
Each case will be presented by an integer n (1<=n<1000000, and n is odd) at first. Following that, n positive integers will be given in a line, all integers will smaller than 2^31. These numbers indicate the card numbers of the presents.n = 0 ends the input.

 

Output

For each case, output an integer in a line, which is the card number of your present.

 

Sample Input

5
1 1 3 2 2
3
1 2 1
0

 

Sample Output

3
2

Hint
Hint
 
use scanf to avoid Time Limit Exceeded

很水的一个题目，一开始没有读懂题意，后来才发现是出现奇数次的数字，只需要异或就行，然后原来开的数组没有删除，依然是用数组输入，结果tle，后来删除了数组，才AC。

#include <stdio.h>

int main(){
	int n,num;
	
	while(~scanf("%d",&n) && n){
		int i,ans = 0;
		
		for(i = 0; i < n;  i ++){
			scanf("%d",&num);
			ans ^= num;
		}
		
		printf("%d\n",ans);
	}
	
	return 0;
}