Greeting Code #include <iostream> int main() { std::cout << "Competition Day!" << '\n'; return 0; } Neighbor Sum Array #include <iostream> #include <vector> using namespace std; int main() { ios::sync_with_stdio(false); cin.tie(nullptr); int len; cin >>...
D. Prefix Reversal Construction A palindrome insertion strategy can transform any sequence by reversing prefixes. Inserting a pattern like abc...cba after a prefix abc... effectively reverses that prefix while leaving subsequent elements unchanged. Key insight: Two flip operations suffice for transf...
Core Concepts and Prerequisites To effectively implement merging operations on range-based data structures, understanding dynamic node allocation and order statistic trees is essential. Standard segment trees often consume excessive memory when built fully; dynamic initialization allowss resources t...
A knapsack problem involves selecting items with given weights and values to maximize total value without exceeding a capacity limit. It appears in resource allocation, scheduling, logistics, and investment scenarios. Problem Categories Binary Knapsack — Each item can be taken at most once. Given n...
Bubble Sort Two-pointer loop, swap when out of order, until the desired element floats to the boundary. function bubbleSort(arr) { const n = arr.length; for (let i = 0; i < n; i++) { for (let j = 0; j < n - i - 1; j++) { if (arr[j] > arr[j + 1]) { [arr[j], arr[j + 1]] = [arr[j + 1], arr[j]]...
Given the root nodes p and q of two binary trees, implement a function to verify if they are structurally identical and contain identical node values. Example: Input: p = [1,2,3], q = [1,2,3] Output: true Approach Two trees are considered identical only when their structures match completely and eve...
Problem A - Dice Magic (NiuKe Beginner Monthly Contest 98) Check if a target number exists within a given array. #include <bits/stdc++.h> using namespace std; long long n, x; long long arr[505]; void solve() { for (int i = 1; i <= n; ++i) { cin >> arr[i]; } for (int i = 1; i <= n;...
Introduction This article presents various implementations of the DSU on Trees technique, also known as 'DSU on Tree'. The method involves processing each node's subtree in a specific order to efficiently compute answers for queries related to subtree properties. Standard DSU Approach The standard i...
Time and Space Complexity of Binary Search Time Complexity — O(log N) Binary search operates by repeatedly dividing the array in half. Each iteration reduces the search space to half of its previous size. Starting with N elements, the size becomes N/2, then N/4, and so forth untill the element is fo...
KMP (Knuth–Morris–Pratt) is a string matching algorithm well suited for finding a single match. For multiple matches, an improved Rabin-Karp is better. Note: If you are preparing for an exam, do not read this article because it follows the original paper, which differs significantly from typical exa...
