Given a non negative integer number num. For every numbers i in the range 0 ≤ i ≤ num calculate the number of 1's in their binary representation and return them as an array. Example 1: Input: 2 Output: [0,1,1] Example 2: Input: 5

Given a string s, find the length of the longest substring without repeating characters. Example 1: Input: s = "abcabcbb" Output: 3 Explanation: The answer is "abc", with the length of 3. Example 2:

See the solutions in a category by number. See the solutions in a category by class. Easy 1. Two Sum Medium 2. Add Two Numbers

See the solutions in a category by number. See the solutions in a category by level. Array 1. Two Sum Binary Search 1. Two Sum

See the solutions in a category by level. See the solutions in a category by class. The Problems: 1. Two Sum 2. Add Two Numbers 3. Longest Substring Without Repeating Characters 6. ZigZag Conversion 338. Counting Bits

You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order, and each of their nodes contains a single digit. Add the two numbers and return the sum as a linked list. You may assume the two numbers do not contain any leading zero, except the number 0 itself. Example 1: Input: l1 = [2,4,3], l2 = [5,6,4] Output: [7,0,8] Explanation: 342 + 465 = 807.

Given a positive integer n, break it into the sum of at least two positive integers and maximize the product of those integers. Return the maximum product you can get. Example 1: Input: 2 Output: 1 Explanation: 2 = 1 + 1, 1 × 1 = 1. Example 2:

The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility) P A H N A P L S I I G Y I R And then read line by line: "PAHNAPLSIIGYIR" Write the code that will take a string and make this conversion given a number of rows:

Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target. You may assume that each input would have exactly one solution, and you may not use the same element twice. You can return the answer in any order. Example 1: Input: nums = [2,7,11,15], target = 9 Output: [0,1]