SingleNumber.java

//136. Single Number

//Given a non-empty array of integers nums, every element appears twice except for one. Find that single one.
//
//You must implement a solution with a linear runtime complexity and use only constant extra space.
//
//
//
//Example 1:
//
//Input: nums = [2,2,1]
//Output: 1
//Example 2:
//
//Input: nums = [4,1,2,1,2]
//Output: 4
//Example 3:
//
//Input: nums = [1]
//Output: 1
//
//
//Constraints:
//
//1 <= nums.length <= 3 * 104
//-3 * 104 <= nums[i] <= 3 * 104
//Each element in the array appears twice except for one element which appears only once.

public class SingleNumber {
    public int singleNumber(int[] nums) {
        int n = 0;
        for(int i = 0; i < nums.length; i++){
            for(int j = i + 1; j < nums.length; j++){
                if(nums[i] == nums[j]){
                    nums[i] = 0;
                    nums[j] = 0;
                }
            }
        }
        for(int k = 0; k < nums.length; k++){
            if(nums[k] != 0)
                n = nums[k];
        }
        return n;
    }
}