1. Problem Summary You are given an integer array nums.Your task is to determine: Important clarifications: Example: 2. Key Insights LIS length alone is not enough This problem extends the classic LIS by also counting how many achieve that length. We track two values per index For each index i: Transition logic For every earlier…

1. Problem Summary You are given an array seats where: You must choose an empty seat such that the distance to the closest occupied seat is maximized, and return that maximum distance. Important characteristics: Example interpretation:If seats = [1,0,0,0,1,0,1], the best position is index 2 or 1 or 3, giving a max distance of 2.…

1. Problem Summary You are given a sorted integer array nums with no duplicates.Your task is to summarize continuous ranges and return them as a list of strings. The formatting rules are: Example interpretation:For input: Output: 2. Key Insights Array is already sorted and unique So we only need to detect breaks in continuity. Consecutive…

1. Problem Summary You are given a 2D matrix with the following properties: Your task is to determine whether a given integer target exists in the matrix.Return: Important details: Example interpretation:If the matrix is: and target = 3 → return trueand target = 13 → return false 2. Key Insights Matrix behaves like a sorted…

1. Problem Summary You are given an integer array nums and an integer k.Your task is to rotate the array to the right by k steps, where: Important details: Example interpretation:If nums = [1,2,3,4,5,6,7] and k = 3, the result becomes: 2. Key Insights Rotations wrap around modulo array length If array length = N:…

1. Problem Summary You are given an integer array nums.Your task is to find the smallest positive integer (greater than 0) that does not appear in the array. Important characteristics: Example interpretation:For input [3, 4, -1, 1], the smallest missing positive is 2. 2. Key Insights The answer is always in the range [1 ……

1. Problem Summary You are given two strings: Your task is to identify and return the extra character that appears in t but not in s. Important characteristics: Example interpretation:If s = “abcd” and t = “abcde”, the answer is ‘e’. 2. Key Insights Counting characters works but is unnecessary You could count occurrences of…

1. Problem Summary You are given two integer arrays: Stations form a circular route, meaning after the last station, you return to station 0. Your task is to: Important constraints: 2. Key Insights Total fuel vs total cost determines feasibility If the total gas available is less than the total cost required: If a starting…

1. Problem Summary You are given two integers low and high.Your task is to return all numbers within this range (inclusive) that have sequential digits, meaning: Examples of sequential digits: Example interpretation:If low = 100 and high = 300, valid results include: 2. Key Insights Sequential digit numbers are limited There are very few valid…

1. Problem Summary You are given a string s consisting of upper-case letters, lower-case letters, and spaces. Your task is to return the length of the last word in the string, where: Example interpretation:For input “Hello World”, the last word is “World” and the result is 5. 2. Key Insights Words are separated by spaces…