Cycle Detection in Linked Lists with Floyd's Algorithm
The problem involves verifying the presence of a closed loop within a sequence of connected nodes. Specifically, one must determine if traversing the next pointers eventually returns to a previously encountered node. While test environments may define connection indices for simulation purposse, the algorithm operates logically without reliance ...
Posted on Tue, 04 Aug 2026 16:56:34 +0000 by DigitalNinja
Understanding Array Structures in Java
Fundamental Properties of Arrays
Arrays serve as a foundational data structure designed to hold a predetermined number of elements. These elements are strictly homogeneous, meaning an array defined for integers cannot store strings or floating-point numbers. This type safety ensures consistency in data handling.
A defining characteristic of arr ...
Posted on Tue, 04 Aug 2026 16:18:16 +0000 by ArneR
Competitive Programming Solutions: Niuke Summer Multi-School Training Camp 2024
Given an integer x, construct a y < x such that gcd(x, y) = x ⊕ y (bitwise XOR).
The solution is to take y = x - lowestSetBit(x). If x is a power of 2, then no solution exists.
#include<iostream>
#include<cmath>
using namespace std;
using ll = long long;
void solve() {
ll x;
cin >> x;
ll lowest_bit = x & ...
Posted on Tue, 04 Aug 2026 16:19:06 +0000 by VLE79E
Understanding Shell Sort: A Generalized Insertion Sort Algorithm
Core Principles of Shell Sort
Shell sort operates as a generalized optimization of the insertion sort algorithm. While standard insertion sort is efficient for small or nearly sorted datasets, its performance degrades significantly on large lists because elements can only move one position at a time. Proposed by Donald Shell in 1959, this algor ...
Posted on Tue, 04 Aug 2026 16:09:19 +0000 by brotherhewd
Designing a Linked List (LeetCode 707)
get(index): Get the value of the index-th node in the linked list. If the index is invalid, return -1.
addAtHead(val): Add a node of value val before the first element of the linked list. After the insertion, the new node will be the first node of the linked list.
addAtTail(val): Append a node of value val as the last element of the linked lis ...
Posted on Sun, 02 Aug 2026 16:56:14 +0000 by quikone
Implementing a Contact Management System in C
Building a Small Address Book in C
Mini Project: Address Book System
Requirements: Store contact information:
Name, Gender, Phone
Maximum capacity: 50 contacts
Functional requirements:
Add a contact
Delete a contact by name
Modify a contact by name
Search contacts by name or phone (supports fuzzy search)
Display all contacts
Exit the system
...
Posted on Sun, 02 Aug 2026 16:21:01 +0000 by benjy
Southwest University for Nationalities 2023 Programming Competition Selection Problems and Solutions
L1-1 Thank You, Karl!
This problem requires outputting a specific formatted string. The output contains an emoticon with escaped backslashes.
Reference Implementation
#include <bits/stdc++.h>
using namespace std;
int main()
{
cout << "Thank You Karl!\\\\(>_<)/" << endl;
return 0;
}
L1-2 It's Fantasy ...
Posted on Sat, 01 Aug 2026 16:26:03 +0000 by bender
Binary Tree Algorithm Challenges: Minimum Difference, Modes, and Lowest Common Ancestor
Finding the Minimum Absolute Difference in a BSTGiven the properties of a Binary Search Tree (BST), an in-order traversal processes nodes in ascending order of their values. Consequently, the smallest absolute difference between any two nodes in the tree must exist between two adjacent nodes in this sorted sequence. We can implement a recursive ...
Posted on Thu, 30 Jul 2026 16:47:13 +0000 by MitchEvans
Topological Sorting: Detecting DAGs and Resolving Competition Rankings
Topological sorting is a fundamental graph algorithm with critical applications in determining whether a directed graph contains cycles. This technique is extensively used in build systems, course scheduling, and dependency resolution.
Problem A: Topological Sort for Directed Acyclic Graphs
The core challenge involves producing a valid topologi ...
Posted on Thu, 30 Jul 2026 16:35:06 +0000 by dlester
Understanding HashCode: Collision Resolution and Practical Implications in HashMap
What is a Hash Collision?
When discussing hash collisions, we need to understand the fundamental issue: different objects processed through the same hash algorithm produce identical hash values.
Consider HashMap's internal structure—a combination of an array with linked lists. When a key-value pair is inserted, the hash code determines which ar ...
Posted on Wed, 29 Jul 2026 16:18:10 +0000 by jonsjava