Easy Bit Manipulation

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2020-05-29

136. Single Number

Similar Question: LeetCode Question 137, LeetCode Question 260

Question:

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

Solution:

Using bit operators bitwise xor ^, it will return 0 if two numbers are same. Finally, it will leave with the single number.

class Solution {
    public int singleNumber(int[] nums) {
        int result = 0;
        for (int i : nums) {
            result ^= i;
        }
        return result;
    }
}