An anagram is a word or phrase formed by rearranging the letters of another word or phrase. For example, “listen” and “silent” are anagrams. This problem asks you to determine if two given strings are anagrams of each other, but it should also work with Unicode characters like emojis or…
First Unique Character In A String – 387. LeetCode
The “First Unique Character in a String” problem asks you to find the index of the first character in a string that appears only one. If no such character exists, return -1. This problem is about efficiently identifying a character that is unique while processing all the characters in the…
Search In Rotated Sorted Array – 33. LeetCode
The “Search in Rotated Sorted Array” problem involves finding a target value in a sorted array that’s been rotated at some unknown pivot. For instance, an array like [4,5,6,7,0,1,2] is a rotation of [0,1,2,4,5,6,7]. You’re given this rotated array and a target value; your goal is to determine the target’s…
Sliding Window Maximum – 239. LeetCode
The “Sliding Window Maximum” problem involves finding the maximum value in a sliding window of a fixed size as it moves across an array. Think of it as looking through a fixed-size frame at a sequence of numbers and finding the biggest number within the frame as you slide it from…
Maximum Product Subarray – 152. LeetCode
The Maximum Product Subarray problem asks you to find the highest possible product from any sequence of consecutive numbers (or “subarray”) within a given list of integers. You’re not just looking for the largest single number, but rather the maximum product you can achieve by multiplying a series of numbers…
Generate Parentheses – 22. LeetCode
The “Generate Parentheses” problem is about creating all combinations of well-formed parentheses for a given number of pairs, n. Each valid combination must have balanced opening and closing parentheses. For example, if n = 3, some valid combinations would be ((())), (()()), (())(), ()(()), and ()()(). Brute-Force Approach In a…
3Sum – 15. LeetCode
The threeSum problem is a classic question that aims to find all unique triplets in an array that add up to zero. Given an integer array nums, the goal is to return a list of lists where each list represents a unique triplet that satisfies this condition. Solving this problem…
Rotate Array – 189. LeetCode
The “Rotate Array” problem on LeetCode asks us to rotate an array of integers to the right by a given number of steps k . This means each element in the array moves k positions to the right, with elements at the end wrapping around to the beginning. The challenge…
Coin Change – 322. LeetCode
The “Coin Change” problem is a classic example of a dynamic programming problem in which we aim to find the minimum number of coins needed to make up a target amount using a given set of coin denominations. This problem is known for testing the ability to optimize for minimal…
Longest Common Subsequence – 1143. LeetCode
The Longest Common Subsequence (LCS) problem is a classic question in computer science. Given two strings, the goal is to find the longest sequence of characters that appears in both strings in the same order (though not necessarily consecutively). This problem is common in fields like bioinformatics for DNA sequence…
