Freaks City

Introduction to Java Enums Java enums are a special data type that allows for a variable to be a set of predefined constants. The values in an enum are implicitly final, static, and public. They provide type safety, making your code more readable and less prone to errors compared to using simple integer or string constants. Enums can have their ...

Intersection Calculation Given two line segments [L1, R1] and [L2, R2], determine their overlapping length. A simple approach uses a frequency array to mark covered positions. #include <iostream> using namespace std; int main() { int L1, R1, L2, R2; int coverage[101] = {0}, overlap = 0; cin >> L1 >> R1 >> L2 ...

203. Remove Linked List Elements Given the head of a linked list and an integer val, remove all nodes with value equal to val and return the new head. public ListNode removeElements(ListNode head, int val) { while (head != null && head.val == val) { head = head.next; } if (head == null) return null; ListNode pre ...

Stacks and queue are foundational linear data structures governed by LIFO and FIFO principles, respectively. This article demonstrates how to implement both using static arrays in C, C#, and C++—with redesigned logic, renamed identifiers, and structural variations while preserving correctness and clarity. Array-Based Stack Implementation A stac ...

Hash structures in Redis allow storage of key-value pairs where the value itself is a collection of field-value mappings, similar to dictionaries in Python or maps in Java. Storing Data Use HSET to insert field-value pairs into a hash: 127.0.0.1:6379> HSET users username john age empty location mars (integer) 3 Retreiving Individual Values ...

Consider an array of (n) integers (a_1, a_2, \cdots, a_n). Two types of operations are supported: Add a value (d) to all elements from index (l) to (r). Query the maximum element within the range ([l, r]). To efficiently handle these operations, we use a segment tree enhanced with lazy propagation. This technique introduces a lazy tag to defe ...

Probabilistic Path Enumeration in Directed Acyclic Graphs Given a directed acyclic graph (DAG) consisting of $V$ vertices and $E$ edges, each edge $e_k$ possesses an independent activation probability $p_k$. The objective is to compute the expected number of functional paths originating from vertex $0$ and terminating at vertex $V-1$. A path is ...

A – Calendar Game Ignoring the year, the losing positions follow the pattern (month + day) % 2 == 1, except for the two special dates 9/30 and 11/30 which allow the next player to flip the parity. #include <bits/stdc++.h> using namespace std; int main() { ios::sync_with_stdio(false); cin.tie(nullptr); int t; cin >> t; ...

Array Algorithms Binary Search Fundamentals Binary search operates on sorted sequences with distinct elements. The algorithm halves the search space repeatedly until locating the target or exhausting the range. Critical Implementation Details: Midpoint Calculation: Use mid = lo + (hi - lo) // 2 instead of (lo + hi) // 2 to prevent integer ove ...

A stack is a linear data structure that restricts insertions and deletions to a single endpoint—referred to as the top—while the opposite fixed end is the bottom. When no elements are present, its an empty stack, and its fundamental behavior follows Last-In-First-Out (LIFO) semantics. Static Stack Using Contiguous Memory This implementation lev ...