💡 Problem Formulation: We aim to find the number of distinct palindromic substrings of size k that can be created using the characters of a given string. For example, given the string “aabb” and k = 2, the output should be 2 since we can form the palindromes “aa” and “bb”. Method 1: Using Hashing … Read more
💡 Problem Formulation: Given a list of integers, the task is to find the number of valid pairs (a, b) such that their sum is an odd number. A pair is considered valid if the two numbers are different and can be picked from the list possibly at different indices. For example, given the list … Read more
💡 Problem Formulation: Ensuring that version numbering follows a consistent and logical pattern is crucial for software management and release control. Developers need to verify if a new version number is correctly incremented from the old one. For instance, the input could be the old version “1.2.3” and the new version “1.2.4”, and the desired … Read more
💡 Problem Formulation: Given a binary tree and an integer k, the challenge is to find all the paths in the tree that consist of exactly k edges. A path in a binary tree is a sequence of nodes where each pair of adjacent nodes has an edge connecting them. The input consists of the … Read more
💡 Problem Formulation: Python developers often encounter the need to filter or count elements based on certain criteria. In this article, we address the specific problem of counting the number of elements within a list that contains an odd number of digits. For instance, if the input is [123, 4567, 89, 5, 3210], the desired … Read more
💡 Problem Formulation: Computing the sum of the first n odd numbers is a common problem that can be addressed using various approaches in Python. Given a positive integer n, the task is to calculate the total of the first n odd numbers in a sequence. For instance, if the input is 5, the desired … Read more
💡 Problem Formulation: Imagine you have a list of strings, and you aim to determine how many of these strings contain a single unique character. For instance, given the list [‘a’, ‘aa’, ‘aaa’, ‘bcbc’, ‘ddd’], the program should output 3 because ‘a’, ‘aa’, and ‘ddd’ contain only one unique character. Method 1: Using a For … Read more
💡 Problem Formulation: Given a binary tree and a range [L, R], we are tasked with finding the number of nodes within this range. The binary tree is a rooted tree where each node contains an integer value. This article will explore various methods to solve this problem in Python. For example, if our binary … Read more
💡 Problem Formulation: In Python, we often face the task of transforming a list by replacing each element with the smallest preceding element. It’s a common challenge when dealing with optimizations or specific algorithms. For example, given the input array [3, 7, 4, 8, 2], the desired output would be [None, 3, 3, 4, 3] … Read more
💡 Problem Formulation: The challenge is to transform an array of integers so that all its elements become equal with the minimum number of operations. An operation is defined as incrementing or decrementing any element by one. Given an input like [1, 2, 3], the desired output is to make all elements equal, for instance, … Read more
💡 Problem Formulation: Python developers often face scenarios where they must apply a specified operation between each element of a list and a single value. For instance, if we have a list [1, 2, 3] and a value 5, and the operation is addition, the desired output should be [6, 7, 8]. Method 1: Using … Read more
💡 Problem Formulation: You have a singly linked list where each node contains a single digit. Those digits form a binary number when read from left to right. Your task is to convert this binary-linked list to its equivalent decimal integer. For example, given the linked list 1 -> 0 -> 1, your function should … Read more