1. Problem Summary You are given an array nums where each element represents the amount of money stored in a house along a street. You must determine the maximum amount of money you can rob, with the restriction that: Example interpretation:If you rob house i, you cannot rob houses i-1 or i+1. 2. Key Insights…

1. Problem Summary You are given: Your task is to: Example interpretation:If the existing intervals are [[1,3], [6,9]] and the new interval is [2,5], after inserting and merging, the output becomes [[1,5], [6,9]]. 2. Key Insights The original intervals are already: This allows a linear scan. Three logical phases occur: Overlapping rule Two intervals overlap…

1. Problem Summary You are given two integers: Your task is to return all unique combinations of exactly k distinct numbers where: The result must contain only valid combinations, and the order of combinations does not matter. Example interpretation:If k = 3 and n = 7, one valid combination is [1, 2, 4] because: 2.…

1. Problem Summary You are given an integer array nums.Your task is to find the contiguous subarray (containing at least one number) that has the maximum product, and return that product. Important characteristics of this problem: Example interpretation:Given [-2, 3, -4], the maximum product subarray is [3, -4], whose product is -12, but the full…

1. Problem Summary You are given the root of a binary tree. Your task is to determine the maximum depth of the tree. The depth of a binary tree is defined as: A leaf node is one that has no left or right child. Example understanding:If the longest path contains nodes [1 → 3 →…

1. Problem Summary You are given the root of a binary tree where each node contains a value of either 0 or 1.Every path from the root to a leaf forms a binary number, where the digits are collected in the order they appear along the path. Your task is to compute the sum of…

You are given a pattern string (consisting of lowercase letters) and a sentence string made of words separated by spaces. Your task: Determine whether the sentence follows the same pattern, meaning: Example: Another example: Another: Another: Problem Understanding This problem is about bijective mapping: For the pattern to match: Logic Explained in Simple English Here’s…

You are given two binary square matrices img1 and img2 of size n x n, containing only 0s and 1s. Your task: Slide one image over the other (up, down, left, right) and determine the maximum number of overlapping 1’s. Example: Explanation:A shift exists that causes 3 overlapping 1s. Problem Understanding Key characteristics: Brute force…

You are given a square matrix mat of size n x n.Your task: Return the sum of the matrix’s primary diagonal and secondary diagonal. Example: Another example: Problem Understanding Important details: Key insight: For each row i, add: And avoid double-count when i == n – 1 – i. Logic Explained in Simple English The…

You are given the roots of two Binary Search Trees (BSTs): Your task: Return a sorted list containing all elements from both trees. Example: Another example: Problem Understanding Important characteristics: So the challenge reduces to: Extract sorted lists from both BSTs, then merge them. This is identical to merging two sorted arrays. Logic Explained in…