single-number-ii

Single Number II

LeetCode #: 137

Difficulty: Medium

Topics: Bit Manipulation.

Problem

Given a non-empty array of integers, every element appears three times except for one, which appears exactly once. Find that single one.

Note:

Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory?

Example 1:

Input: [2,2,3,2]
Output: 3

Example 2:

Input: [0,1,0,1,0,1,99]
Output: 99

Solution Explanation

Reference:

• Detailed explanation and generalization of the bitwise operation method for single numbers by fun4LeetCode

• Challenge me , thx by againest1

Complexity Analysis

Time complexity: O(n)

Space complexiy: O(1)