[LeetCode]Single Number
Given an array of integers, every element appears twice except for one. Find that single one.
Note: Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory?
思考：位运算。
class Solution {
public:
int singleNumber(int A[], int n) {
// IMPORTANT: Please reset any member data you declared, as
// the same Solution instance will be reused for each test case.
int ret=0;
while(n--)
{
ret^=A[n];
}
return ret;
}
};