# JavaScript

June 4, 2019

### Prime Number of Set Bits in Binary Representation

Given two integers L and R, find the count of numbers in the range [L, R] (inclusive) having a prime number of set bits in their binary representation. (Recall that the number of set bits an integer has is the number of 1s present when written in binary.

June 3, 2019

### Second Minimum Node In a Binary Tree

Given a non-empty special binary tree consisting of nodes with the non-negative value, where each node in this tree has exactly two or zero sub-node. If the node has two sub-nodes, then this node's value is the smaller value among its two sub-nodes.

June 2, 2019

### Robot Bounded In Circle

On an infinite plane, a robot initially stands at (0, 0) and faces north. The robot can receive one of three instructions: "G": go straight 1 unit; "L": turn 90 degrees to the left; "R": turn 90 degress to the right. The robot performs the instructions given in order, and repeats them forever.

June 1, 2019

### Reshape the Matrix

You're given a matrix represented by a two-dimensional array, and two positive integers r and c representing the row number and column number of the wanted reshaped matrix, respectively.

May 31, 2019

### Pairs of Songs With Total Durations Divisible by 60

In a list of songs, the i-th song has a duration of time[i] seconds. Return the number of pairs of songs for which their total duration in seconds is divisible by 60. Formally, we want the number of indices i < j with (time[i] + time[j]) % 60 == 0.

May 30, 2019

### Remove All Adjacent Duplicates In String

Given a string S of lowercase letters, a duplicate removal consists of choosing two adjacent and equal letters, and removing them. We repeatedly make duplicate removals on S until we no longer can.

May 29, 2019

### Remove Outermost Parentheses

A valid parentheses string is either empty (""), "(" + A + ")", or A + B, where A and B are valid parentheses strings, and + represents string concatenation. For example, "", "()", "(())()", and "(()(()))" are all valid parentheses strings.

May 28, 2019

### Search a 2D Matrix

Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the following properties: Integers in each row are sorted from left to right. The first integer of each row is greater than the last integer of the previous row.

May 27, 2019

### Minimum Size Subarray Sum

Given an array of n positive integers and a positive integer s, find the minimal length of a contiguous subarray of which the sum ≥ s. If there isn't one, return 0 instead.

May 26, 2019

### Diagonal Traverse

Given a matrix of M x N elements (M rows, N columns), return all elements of the matrix in diagonal order as shown in the below image.

May 25, 2019

### Valid Parentheses

Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.

May 24, 2019

### First Missing Positive

Given an unsorted integer array, find the smallest missing positive integer.

May 23, 2019

### Palindromic Substrings

Given a string, your task is to count how many palindromic substrings in this string. The substrings with different start indexes or end indexes are counted as different substrings even they consist of same characters.

May 21, 2019

### Palindrome Number

Determine whether an integer is a palindrome. An integer is a palindrome when it reads the same backward as forward.

May 19, 2019

### Remove Duplicates from Sorted Array

Given a sorted array nums, remove the duplicates in-place such that each element appear only once and return the new length. Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory.

May 18, 2019

### Lowest Common Ancestor of a Binary Tree

Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree. The lowest common ancestor is defined between two nodes p and q as the lowest node in T that has both p and q as descendants.

May 17, 2019

### Valid Perfect Square

Given a positive integer num, write a function which returns True if num is a perfect square else False.

May 16, 2019

### String to Integer

The function first discards as many whitespace characters as necessary until the first non-whitespace character is found. Then, starting from this character, takes an optional initial plus or minus sign followed by as many numerical digits as possible, and interprets them as a numerical value.

May 15, 2019

### Merge Two Sorted Lists

Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists.

May 14, 2019

### Two sum

Given an array of integers, return indices of the two numbers such that they add up to a specific target. You may assume that each input would have exactly one solution, and you may not use the same element twice.

May 14, 2019

### Reorganize String

Given a string str, check if the letters can be rearranged so that two characters that are adjacent to each other are not the same. If possible, output any possible result. If not possible, return the empty string.

May 13, 2019

### How to implement Heap data structure in JavaScript?

A heap is a tree-based data structure which satisfies the heap property, if the parent node is greater than the child node is called max-heap or if the parent node is less than the child node is called min-heap.