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...
Data Structures Mo's Algorithm Standard Mo's Algorithm Used to solve problems like P1494 [National Training Team] Little Z's Socks. #include <bits/stdc++.h> #define int long long using namespace std; const int MAXN = 200010; struct Query { int l, r, idx; }; struct Fraction { int numerator, den...
A specialized variant of the Sieve of Eratosthenes can simultaneously tag integer primality and record the count of prime factors for each composite. This technique is particularly effective when searching for numbers within a range whose total number of prime factors (with multiplicity) equals a gi...
Objective Implement a function to determine if a given string represents a valid numeric value, including integers, decimals, and numbers in scientific notation. Examples of Valid Inputs "+100", "5e2", "-123", "3.1416", "-1E-16" Examples of Invalid I...
Given N closed intervals [x_i, y_i], split them into the least number of groups such that all intervals in each group are pairwise non-overlapping (including endpoints). Output this minimum count. Input Format The first line contains an integer N, the number of intervals. The next N lines each conta...
Algorithm LogicThe task requires implementing a function that calculates the frequency of a specific digit (0-9) within a given integer. The primary challenge involves handling the sign of the input number and the edge case where the input is zero.Since the input integer is passed as a const int, it...
