Leetcode Solution - Best Time to Buy and Sell Stock
Problem Statement You are given an array prices where prices[i] is the price of…
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Graph Topological Sorting - Build System Order Example
Graph Topological Sorting This is a well known problem in graph world…
Binary Tree - Level Order Traversal
Problem Statement Given a Binary tree, print out nodes in level order traversal…
Four Sum - Leet Code Solution
Problem Statement Given an array nums of n integers and an integer target, are…
Leetcode - Rearrange Spaces Between Words
Problem Statement You are given a string text of words that are placed among…
Leetcode - Maximum Non Negative Product in a Matrix
Problem Statement You are given a rows x cols matrix grid. Initially, you are…
Leetcode - Split a String Into the Max Number of Unique Substrings
Problem Statement Given a string s, return the maximum number of unique…
Crawler Log Folder - minimum number of operations needed to go back to the main folder after the change folder operations.
Problem The Leetcode file system keeps a log each time some user performs a…
Replace all spaces in a string with %20
Problem Statement Replace all spaces in a string with ‘%20’ (three characters…
Determine if a string has all unique characters
Problem Implement an algorithm to determine if a string has all the characters…
Valid Palindrome - Leet Code Solution
Problem Statement Given a string, determine if it is a palindrome, considering…
Valid Anagrams - Leet Code Solution
Problem Statement Given two strings s and t , write a function to determine if t…
First Unique Character in a String - Leet Code Solution
Problem Statement Given a string, find the first non-repeating character in it…
Reverse String - Leet Code Solution
Problem Statement Write a function that reverses a string. The input string is…
Rotate Image - Leet Code Solution
Problem Statement You are given an n x n 2D matrix representing an image, rotate…
Validate Sudoku - Leet Code Solution
Problem Statement Determine if a 9x9 Sudoku board is valid. Only the filled…
Plus One - Leet Code Solution
Problem Statement Given a non-empty array of digits representing a non-negative…
Move Zeroes - Leet Code Solution
Problem Statement Given an array nums, write a function to move all 0’s to the…
Intersection of Two Arrays-II - Leet Code Solution
Problem Statement Given two arrays, write a function to compute their…
Single Number - Leet Code Solution
Problem Statement Given a non-empty array of integers, every element appears…
Find if Array contains Duplicate Number - Leet Code Solution
Problem Statement Given an array of integers, find if the array contains any…
Maximum Length of Subarray With Positive Product - Leet Code Solution
Problem Statement Maximum Length of Subarray With Positive Product. Given an…
Rotate Array - Leet Code Solution
Problem Statement Given an array, rotate the array to the right by k steps…
Calculate Max Profit - Buy and Sell Stocks Multiple Times - Leet Code Solution
Problem Statement Say you have an array prices for which the ith element is the…
Remove Duplicates from Sorted Array - Leet Code Solution
Problem Statement Given a sorted array nums, remove the duplicates in-place such…
Binary Tree Data Structure
A Binary tree is a data structure which has two children nodes attached to it…
Binary Search Tree (BST) Data Structure
A Binary Search tree (BST) is a data structure which has two children nodes…
How to calculate First Common Ancestor of two Nodes in Binary Tree
First try to understand question. Its a binary tree, not a binary search tree…
Swap Nodes Pairs in Link List - Leet Code Solution
Problem Statement Given a linked list, swap every two adjacent nodes and return…
Three Sum Closest - Leet Code Solution
Problem Statement Given an array nums of n integers and an integer target, find…
Three Sum - Leet Code Solution
Problem Statement Given an array nums of n integers, are there elements a, b, c…
Convert Roman to Integer number - Leet Code Solution
Problem Statement Roman numerals are represented by seven different symbols: I…
Longest Common Prefix - Leet Code Solution
Problem Statement Write a function to find the longest common prefix string…
Integer to Roman conversion - Leet Code Solution
Problem Statement Roman numerals are represented by seven different symbols: I…
Container with Most Water - Leet Code Solution
Problem Statement Given n non-negative integers a1, a2, …, an , where each…
Check whether an integer number given is palindrome or not - Leet Code Solution
Problem Statement Determine whether an integer is a palindrome. An integer is a…
Remove nth Node from Last - Leet Code Solution
Problem Statement Given a linked list, remove the n-th node from the end of list…
How to calculate angle between hour and minute hand, given a time
This problem is a simple mathematical calculation. Lets start deriving some…
Convert String to Integer - atoi - Leet Code Solution
Problem Statement Implement atoi which converts a string to an integer…
Check whether number is palindrome or not - Leet Code Solution
Problem Statement Determine whether an integer is a palindrome. An integer is a…
Zigzag Pattern String Conversion - Leet Code Solution
Problem Statement The string “PAYPALISHIRING” is written in a zigzag pattern on…
Longest Palindrome Substring - Leet Code Solution
Problem Statement Given a string s, find the longest palindromic substring in s…
Reverse digits of a signed integer - Leet Code Solution
Problem Statement Given a signed integer, reverse digits of an integer. Return…
Find the Median of Two Sorted Arrays - Leet Code Solution
Problem Statement There are two sorted arrays nums1 and nums2 of size m and n…
Longest Substring without repeating characters - Leet Code Solution
Problem Statement Given a string, find the length of the longest substring…
Add two numbers(reverse order) link list Problem - Leet Code Solution
Problem Statement You are given two non-empty linked lists representing two non…
Min Priority Queue Implementation with Heap Data structure
Min Priority Queue is a data structure which manage a list of keys(values). And…
Max Priority Queue Implementation with Heap Data structure
Max Priority Queue is a data structure which manage a list of keys(values). And…
Two Sum Problem - Leet Code Solution
Problem Statement Given an array of integers, return indices of the two numbers…
Index for Coding Problems
Sorting Problems Merge Sort Quick Sort Heap Sort Bubble Sort Selection Sort…