Freaks City

Given a string s and an integer k, the objective is to determine the highest possible count of vowel letters within any contiguous substring of length k. Vowel letters are defined as 'a', 'e', 'i', 'o', 'u'. A sliding window approach provides an efficient solution. The algorithm first calculates the vowel count in the initial window of size k. ...

Core Concept of Dynamic Programming Dynamic Programming (DP) is an algorithmic technique used when a problem exhibits overlapping subproblems and optimal substructure. Unlike greedy algorithms—which make locally optimal choices without considering previous states—DP builds solutions incrementally, where each state is derived from one or more pr ...

House Robber I - Linear Array Problem The classic House Robber problem involves maximizing the amount of money that can be stolen from a line of houses, where adjacent houses cannot be robbed on the same night. class Solution { public: int maxLoot(vector<int>& values) { int houseCount = values.size(); if (houseCoun ...

39. Combination Sum Problem: https://leetcode.cn/problems/combination-sum/description/ Find all unique combinations of candidates where the chosen numbers sum to target. The same number may be used a unlimited number of times. class Solution { public: vector<vector<int>> combinationSum(vector<int>& candidates, int targ ...

Given an integer array nums, construct a 2D array that satisfies the following conditions: The 2D array should contain only elements from the array nums. Each row of the 2D array must consist of distinct itnegers. The number of rows should be minimized. Return any valid result. If multiple solutions exist, any one is acceptable. Note: Rows in ...

Given two singly-linked lists that are already sorted in ascending order, produce a single sorted linked list that interleaves all node from both input lists. Examples Input: list1 = [1, 2, 4], list2 = [1, 3, 4] Output: [1, 1, 2, 3, 4, 4] Input: list1 = [], list2 = [] Output: [] Input: list1 = [], list2 = [0] Output: [0] Implementation strate ...

Minimal Absolute Difference in BST Since an in-order traversal of a binary search tree produces a sorted sequence, the smallest absolute difference between any two nodes corresponds to the minimal gap between adjacent elements in this sequence. The strategy involves tracking the previously visited node and comparing its value with the current n ...

203. Remove Linked List Elements Given the head of a linked list and an integer val, remove all nodes with value equal to val and return the new head. public ListNode removeElements(ListNode head, int val) { while (head != null && head.val == val) { head = head.next; } if (head == null) return null; ListNode pre ...

Swapping Nodes in Pairs Problem: Given a linked list, swap every two adjacent nodes and return its head. Iterative Approach: class ListNode { int val; ListNode next; ListNode(int val) { this.val = val; } } class Solution { public ListNode swapPairs(ListNode head) { if (head == null || head.next == null) { ...

LeetCode 343: Integer Break Given an integer n, break it into the sum of k positive integers, where k >= 2, and maximize the product of those integers. Return the maximum product you can get. Dynamic Programmign Approach The problem can be solved using dynamic programming. The key insight is that the maximum product for a number i depends on ...