HDU 1563 【Find your present!】

[align=left]Problem Description[/align]
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.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.

[align=left]Input[/align]
The input file will consist of several cases.
Each case will be presented by an integer n (1<=n<=200, and n is odd) at first. Following that, n positive integers will be given in a line. These numbers indicate the card numbers of the presents.n = 0 ends the input.

[align=left]Output[/align]
For each case, output an integer in a line, which is the card number of your present.

[align=left]Sample Input[/align]

5
1 1 3 2 2
3
1 2 1
0

[align=left]Sample Output[/align]

3
2

找不同。。。。用数组超时，只得位运算

#include<iostream>
using namespace std;
int main()
{
int N=0,result=0,num=0;
while(true)
{
cin>>N;
if(N==0)
break;
else
{
for(int i=0; i<N; i++)
{
cin>>num;
result=result^num;
}
cout<<result<<endl;
}
result=0;
}
}