Emily Rosemary Collins

💡 Problem Formulation: The specific challenge discussed in this article is to identify the longest substring within a given string that contains exactly k unique characters. For instance, in the string “aabbcc”, the longest substring with 2 unique characters is either “aabb” or “bbcc”, both of which have a length of 4. Our goal is … Read more

💡 Problem Formulation: The task is to determine the least amount of operations needed to preprocess two strings so that they become equal. Each preprocessing move can be any kind of manipulation that transforms the string towards equivalence. For instance, given the strings “abcde” and “abfde”, the minimum preprocess move required is one: changing ‘c’ … Read more

💡 Problem Formulation: Imagine you have a 2D matrix where each row represents a collection of elements. Your task is to find the set of distinct elements that are common to all rows in the matrix. For example, given the matrix [[1, 2, 3], [2, 3, 4], [1, 3, 5]], the desired output would be … Read more

💡 Problem Formulation: Given a matrix (a list of lists in Python) and a specific cell (identified by its row and column indices), the task is to calculate the sum of all elements in the matrix except those that are in the same row or column as the specified cell. For example, given the matrix … Read more

💡 Problem Formulation: The goal is to find all substrings within a given string that contains all five vowels (a, e, i, o, u). For example, given the input string “I love Python programming”, the desired output would be a list of substrings that include all vowels, such as [“love Pytho”, “ove Python progr”]. This … Read more

💡 Problem Formulation: In the realm of binary trees, a perfect subtree is a subtrees that is both full and complete, meaning all its internal nodes have two children and all leaves are at the same depth. The challenge is to find the largest such subtree within a given binary tree. For instance, if we … Read more

💡 Problem Formulation: Given a list of integers, the challenge is to find all subsequences where the result of bitwise AND or bitwise OR operations on all elements yields the maximum possible value. For example, in a list [1, 2, 3], the subsequence [2, 3] has the maximum bitwise AND (2) and the subsequence [1, … Read more

💡 Problem Formulation: This task involves identifying the first character from String A that appears earliest in String B, given two strings. For example, if String A is “apple” and String B is “plane”, the desired output is “a” as it appears at index 0 in String B. This problem is common in text processing … Read more

💡 Problem Formulation: We are tasked to identify the maximum sized rectangle consisting of 1’s in a binary matrix, with the allowance of swapping columns to maximize the rectangle’s area. Given a 2D binary matrix, such as [[0, 1, 0, 1, 0], [1, 1, 0, 1, 1], [0, 1, 1, 0, 0]], the output should … Read more

💡 Problem Formulation: This article focuses on finding the total count of palindromic substrings within a given string, which are subsequences that read the same forward and backward. Given an input string, our goal is to calculate how many distinct palindromic substrings exist when the input is considered in its sorted form. For instance, if … Read more

💡 Problem Formulation: When dealing with geometrical problems in programming, it’s common to encounter tasks such as finding the coordinates of the fourth vertex of a rectangle when three vertices are known. This task is especially relevant in computer graphics, computer vision and game development. For instance, given vertices A(2, 4), B(6, 4), and C(2, … Read more

💡 Problem Formulation: In a stream of characters, the challenge is to efficiently determine the first character that does not repeat itself. This is a common problem in software development where, given an input like “aabbcddeff”, the desired output is “c”, because it’s the first character that appears only once in the stream. Method 1: … Read more