Freaks City

Problem 1: Lexicographical String Matching Solution Since the problem involves lexicographical order, a trie data structure is suitable. To find the solution, use a greedy approach. Determine if the string ending at the current node is the answer. If not, continue to traverse to one of the child nodes. The process is illustrated in the followi ...

You are given a 1-indexed array of integers numbers that is already sorted in non-decreasing order. Find two numbers such that they add up to a specific target number. Let these two numbers be numbers[index1] and numbers[index2] where 1 <= index1 < index2 <= numbers.length. Return the indices of the two numbers, index1 and index2, as a ...

Single Number Given a non-empty array of integers where every element appears twice except for one, find that single one using bitwise XOR. The XOR operation has two critical properties: commutativity (a ^ b == b ^ a) and identity (x ^ x == 0 and x ^ 0 == x). Consequently, XORing all numbers in the array cancels out the pairs, leaving the uniqu ...

Problem We are given a sequence (a_1, a_2, \ldots, a_n) of length (n) and (m) distinct integers (b_1, b_2, \ldots, b_m). We perform a fierce cut on sequence (a) based on the numbers in (b). Specifical, for each position (i) where (a_i) equals some (b_j), we remove the element at that position, splitting the current sequence/fragment into two fr ...

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 ...