137. Single Number II.js

// Given an integer array nums where every element appears three times except for one, which appears exactly once. Find the single element and return it.

// You must implement a solution with a linear runtime complexity and use only constant extra space.

// Example 1:

// Input: nums = [2,2,3,2]
// Output: 3
// Example 2:

// Input: nums = [0,1,0,1,0,1,99]
// Output: 99

const singleNumber = nums => {
	nums.sort()
	for (let i = 0; i < nums.length; i += 3) {
		if (nums[i] !== nums[i + 1]) return nums[i]
	}
}

// const singleNumber = nums => {
// 	for (let key of nums) {
// 		if (nums.indexOf(key) === nums.lastIndexOf(key)) return key
// 	}
// }