Given a string composed exclusively of 'P', 'A', and 'T' characters, determine the total number of contiguous 'PAT' substrings. Each 'PAT' substring consists of a 'P' flolowed by an 'A' followed by a 'T', with characters in sequence but not necessarily adjacent. The result must be modulo 1000000007...
Swapping Adjacent Nodes in a Linked List The core idea involves using a dummy head node to simplify edge cases and ensure consistent operations on the first node. When swapping node pairs, careful attention must be paid to preserving references before reassigning pointers. Key considerations: Use a...
This problem can be effectively solved using a Breadth-First Search (BFS) algoritmh. The core idea is to explore possible states, where a state is defined by the positions of two characters and the number of steps taken to reach that state. We can represent a state using a structure that stores the...
To construct an n×n matrix where no two adjacent elements differ by exactly 1, we can implement a column-based shifting approach. For odd-numbered columns, shift all elements upward by one position, moving the overflow element to the bottom. This construction works for all cases except n=1, where n...
Bubble Sort **1. Core Concept:**Starting from the beginning of an unordered sequence, compare adjacent elements and swap them if needed to place larger (or smalller) values at the end of the sorted portion. This process continues until all elements are properly ordered. 2. Execution Flow****The bubb...
Given an integer array prices where prices[i] represents the stock price on day i, determine the maximum profit achievable. You may engage in multiple transactions (buy one and/or sell one share of the stock each day) but can hold at most one share at any time. Buying and selling on the same day is...
Exercise 2-1: Programming in C is fun! This task requires printing a specific string to the console. #include <stdio.h> int main() { printf("Programming in C is fun!"); return 0; } Exercise 2-3: Output Inverted Triangle Pattern Prints an inverted triangle pattern using asterisks and...
Understanding the Problem The objective is to verify if a given integer is a palindrome. A palindrome reads the same backward as forward. For integers, this means that if we reverse the sequence of digits, the value remains identical. The problem imposes a strict constraint: the solution must not us...
The Knuth-Morris-Pratt (KMP) algorithm reduces string matching complexity from quadratic O(N×M) to linear O(N+M) by eliminating redundant character comparisons. Instead of backtracking the text pointer upon a mismatch, the algorithm leverages precomputed structural information about the patern to sh...
Problem Set Overview This article presents solutions to five algorithmic problems from Meituan's 2024 Spring campus recruitment online assessment for software engineering positions. Each problem requires specific algorithmic techniques ranging from prefix sum optimization to union-find data structur...