No136.single-number.cs

/*
 * Difficulty:
 * Easy
 *
 * Desc:
 * Given a non-empty 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?
 *
 * Example 1:
 * Input: [2,2,1]
 * Output: 1
 *
 * Example 2:
 * Input: [4,1,2,1,2]
 * Output: 4
*/

public class Solution {
    public int SingleNumber(int[] nums) {
        int num = 0;
        foreach (int n in nums) num ^= n;
        return num;
    }
}