Single Number

https://leetcode.com/problems/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?

public class Solution {
    public int singleNumber(int[] nums) {
        int ans=0;
        int len=nums.length;
        for(int i=0;i<len;i++){
            ans^=nums[i];
        }
        return ans;
    }
}