Leetcode-single Number


题目描述

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?

代码

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.
		if(A == NULL || n == 0)
			return 0;
		int result = A[0];
		for(int i = 1; i < n; i++)
			result = result ^ A[i];
		return result;
		}
	};