Iterator of set

136. Single Number

Given an array of integers, every element appears twice except for one. Find that single one. Solution:  

442. Find All Duplicates in an Array

Description: https://leetcode.com/problems/find-all-duplicates-in-an-array/description/ Code:  

Time & Space: O(n) & O(1)

448. Find All Numbers Disappeared in an Array

Description: https://leetcode.com/problems/find-all-numbers-disappeared-in-an-array/description/ Code:  

Code for fastest algorithm:  

Time & Space: O(n) & O(1)

495. Teemo Attacking

Description: https://leetcode.com/problems/teemo-attacking/description/ Code:  

Time & Space: O(n) & O(1)

485. Max Consecutive Ones

Description: https://leetcode.com/problems/max-consecutive-ones/description/ Code:  

Time & Space: O(n) & O(1)

628. Maximum Product of Three Numbers

Description: https://leetcode.com/problems/maximum-product-of-three-numbers/description/ Code:

Time & Space: O(n) & O(1)

621. Task Scheduler

Description: https://leetcode.com/problems/task-scheduler/description/ Code:  

Time & Space: Record: O(1) Sort: O(nlogn) Calculate idle: O(1) Space: O(1)

611. Valid Triangle Number

Description: https://leetcode.com/problems/valid-triangle-number/description/ Algorithm1: Use for loop for three times. It works but slow (beats 23.60%) Code1:  

Timing & Space: O(n^3) & O(1)   Algorithm2:   Code2:

  Timing & Space: Time: Worst: O(n^2) Best: O(1) Space: O(1)