💡 Problem Formulation: We want to identify an integer x such that x divides every element of an array except for exactly one element. For instance, given the array [15, 3, 6], the integer 3 is a divisor for all elements except for the number 6, making it our target output. Method 1: Brute Force … Read more
💡 Problem Formulation: The challenge is to locate a position within an array such that the product of elements in the subarray to the left is equal to the product of elements in the subarray to the right. Given an input array like [1, 2, 3, 6, 5, 6], the desired output is the index … Read more
💡 Problem Formulation: You have an array where initially, the sequence of elements decreases and then strictly increases, or vice versa—formulating a “turning point” or “peak” in the sequence. The task is to identify the index of this turning element. For instance, with an input array [5, 4, 3, 2, 3, 4, 5], the output … Read more
💡 Problem Formulation: Consider a given mapping where digits are associated with certain characters, similar to the way digits are linked to letters on a telephone keypad. The problem involves finding all possible strings that can be formed from the characters corresponding to a given sequence of digits. For instance, if ‘2’ maps to ‘abc’ … Read more
💡 Problem Formulation: Given a binary matrix (a 2D list) where ‘0’ represents an empty space and ‘1’ signifies any arbitrary blockage, the challenge is to find all the rectangles composed entirely of ‘0’s. These rectangles may vary in size and position across the matrix, and the desired output is a list of coordinates that … Read more
💡 Problem Formulation: The task at hand is to devise methods in Python that can efficiently locate and return all the distinct palindromic substrings within a given string. For instance, given the input string “aabbbaa”, the desired output would be a collection of substrings like [“aa”, “bb”, “bbb”, “aabbaa”], including duplicates only if they occur … Read more
💡 Problem Formulation: Given a postorder traversal of a binary search tree (BST), the task is to reconstruct the original BST. The postorder traversal is a sequence of values visited as per postorder traversal of the BST. For instance, if the input postorder array is [1, 3, 2, 5, 7, 6, 4], the desired output … Read more
💡 Problem Formulation: A primorial prime is a prime number that is one less or one more than a primorial. The primorial of a number is the product of the first n primes. Our objective is to determine whether a given number is a primorial prime. If we take the input 30, for example, the … Read more
💡 Problem Formulation: What is an Achilles number? An Achilles number is a number that is powerful, meaning all of its prime factors are squared, but it is not a perfect power (i.e., it cannot be expressed as m^n for any integers m > 1 and n > 1). In this article, we explore five … Read more
💡 Problem Formulation: The task is to identify all unique substrings within a provided string that read the same backwards as forwards, known as palindromes. For example, given the input string “aabbbaa”, the desired output should be a set of distinct palindromes such as {“a”, “aa”, “b”, “bb”, “bbb”, “abbba”, “aabbbaa”}. Method 1: Brute Force … Read more
💡 Problem Formulation: In Python, checking if a number is a “Trojan number”—a number that remains the same when its digits are squared and concatenated—requires specific checks and computations. The goal is to input a number and determine whether it is a Trojan number. For instance, the input 248 should return True since squaring and … Read more
💡 Problem Formulation: This article addresses the challenge of identifying strings where each character is lexicographically greater than its immediate follower. For instance, given the input ‘cbad’, the desired output is ‘true’ since ‘c’ > ‘b’, ‘b’ > ‘a’, and ‘a’ > ‘d’. Conversely, for ‘abcd’, the output should be ‘false’ as the sequence does … Read more