LeetCode-in-All

136. Single Number

Easy

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:

Solution

impl Solution {
    pub fn single_number(nums: Vec<i32>) -> i32 {
        let mut res = 0;
        for num in nums {
            res ^= num;
        }
        res
    }
}