Freaks City

Problem Statement Given two strings s and t, and an integer k, determine if it's possible to extract two non-overlapping substrings of length k from s such that when concatenated, the resulting string contians t as a contiguous substring. Approach Problem Analysis: The solution involves checking if t can be formed by combining parts of two no ...

Implementing strStr() with the KMP Algorithm Given a haystack string and a needle string, locate the index of the first occurrence of the needle. The Knuth–Morris–Pratt (KMP) algorithm avoids redundant comparisons by precomputing a prefix table (often called the LPS – Longest Proper Prefix which is also Suffix – array). First, construct the LPS ...

Problem Description Given a non-strictly increasing (sorted with possible duplicates) integer aray nums, remove the duplicates in-place succh that each unique element appears only once. Maintain the relative order of the unique elements and return the number of unique elements in nums. Let k be the count of unique elements. To pass the test cas ...

Swapping Adjacent Nodes in Pairs Manipulating node connections uniformly requires a sentinel (dummy) node to eliminate edge cases for the head element. To exchange adjacent pairs, position a reference pointer immediately before the pair undergoing modification. The iterative approach tracks three critical references: the node preceding the pair ...

Swapping Adjacent Nodes in a Linked ListSwapping nodes in pairs requires careful pointer manipulation to maintain the integrity of the list structure. The core idea involves processing two nodes at a time, reversing their connection order while preserving links to neighboring nodes.A dummy header node simplifies edge cases by providing a consis ...

Binary Search Implementation Given a sorted integer array nums with distinct elements and a target value, the objective is to locate the index of the target. If the target is not present, the function should return -1. Binary search efficiently reduces the search space by half in each iteration, but the implementation must strictly adhere to co ...

Minimum Size Subarray Sum Given an array of positive integers nums and a positive integer target, find the minimal length of a contiguous subarray whose sum is greater than or equal to target. If no such subarray exists, return 0. Examples: Input: target = 7, nums = [2,3,1,2,4,3]Output: 2Explanation: The subarray [4,3] has the minimal lengt ...

Problem: 24. Swap Nodes in Pairs To swap two adjacent nodes, we need a pointer standing just before the pair. A dummy sentinel node placed before the head simplifies edge cases. The traversal pointer curr starts at the sentinel. Swapping involves rerouting next pointers in three steps while preserving references that might be lost. The loop con ...

Table of Contents Introduction Remove Linked List Elements (LeetCode--203) Design Linked List (LeetCode--707) Reverse Linked List (LeetCode--206) Swap Nodes in Pairs (LeetCode--24) Remove Nth Node From End of List (LeetCode--19) Linked List Cycle II (LeetCode--142) Introduction Following the Code Thinking Record series, this article explores ...

Squares of a Sorted Array (LeetCode 977) The challenge in squaring a sorted array that contaisn negative numbers is that the largest squares can appear at both ends of the array. While a naive solution involves squaring every element and then sorting the array in $O(n \log n)$ time, a more efficient $O(n)$ approach utilizes the two-pointer tech ...