Problem Design a food rating system that can do the following: Modify the rating of a food item listed in the system. Return...

Problem A sequence x₁, x₂, ..., xₙ is Fibonacci-like if: n >= 3 xᵢ + xᵢ₊₁ == xᵢ₊₂ for all i + 2 <= n Given a strictly...

Problem Given an array of integers arr, return the number of subarrays with an odd sum. Since the answer can be very large, r...

Problem You are given an integer array nums. The absolute sum of a subarray [numsₗ, numsₗ₊₁, ..., numsᵣ₋₁, numsᵣ] is abs(nums...

Problem You have a browser of one tab where you start on the homepage and you can visit another url, get back in the history ...

Problem You are given an integer n representing the size of a 0-indexed memory array. All memory units are initially free. Yo...

Problem There is an undirected tree with n nodes labeled from 0 to n - 1, rooted at node 0. You are given a 2D integer array ...

Problem Given two integer arrays, preorder and postorder where preorder is the preorder traversal of a binary tree of distinc...

Problem Given a binary tree with the following rules: root.val == 0 For any treeNode: If treeNode.val has a value x and tre...

Problem Given an array of strings nums containing n unique binary strings each of length n, return a binary string of length ...

Problem You are given an 0-indexed integer array prices where prices[i] denotes the number of coins needed to purchase the (i...

Problem A happy string is a string that: consists only of letters of the set ['a', 'b', 'c']. s[i] != s[i + 1] for all value...

Problem You are given m arrays, where each array is sorted in ascending order. You can pick up two integers from two differen...

Problem You are given a 0-indexed string pattern of length n consisting of the characters 'I' meaning increasing and 'D' mean...

Problem Design a data structure to find the frequency of a given value in a given subarray. The frequency of a value in a sub...

Problem You have n tiles, where each tile has one letter tiles[i] printed on it. Return the number of possible non-empty sequ...

Problem Given an integer n, find a sequence that satisfies all of the following: The integer 1 occurs once in the sequence. ...

Problem Given a positive integer n, return the punishment number of n. The punishment number of n is defined as the sum of th...

Problem You have a 2-D grid of size m x n representing a box, and you have n balls. The box is open on the top and bottom sid...

Problem Design an algorithm that accepts a stream of integers and retrieves the product of the last k integers of the stream....

Problem In the universe Earth C-137, Rick discovered a special form of magnetic force between two balls if they are put in hi...

Problem You are given a 0-indexed array nums consisting of positive integers. You can choose two indices i and j, such that i...

Problem Given two strings s and part, perform the following operation on s until all occurrences of the substring part are re...

Problem You are given a 0-indexed integer array nums. A pair of indices (i, j) is a bad pair if i < j and j - i != nums[j]...

Problem Given an integer array nums sorted in non-decreasing order, remove some duplicates in-place such that each unique ele...

Problem Design a number container system that can do the following: Insert or Replace a number at the given index in the sys...

Problem You are given an m x n integer array grid. There is a robot initially located at the top-left corner (i.e., grid[0][0...

Problem You are given an integer limit and a 2D array queries of size n x 2. There are limit + 1 balls with distinct labels i...

Problem Given an array nums of distinct positive integers, return the number of tuples (a, b, c, d) such that a * b = c * d w...

Problem There is an integer array nums sorted in non-decreasing order (not necessarily with distinct values). Before being pa...

Problem You are given a 0-indexed 2D matrix grid of size m x n, where (r, c) represents: A land cell if grid[r][c] = 0, or A...

Problem There are a total of numCourses courses you have to take, labeled from 0 to numCourses - 1. You are given an array pr...