Leetcode: SingleNumber I

题目：

Given an array of integers, every element appearstwiceexcept for one. Find that single one.

Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory?

解答：

int singleNumber(int A[], int n)
{
  int ans = 0;
  for (int i = 0; i < n; i++)
  {
    ans ^= A[i];//相同的数字经过异或运算结果为0
  }
  return ans;
}

于是，我深深领悟到了位运算符的魅力。