Solutions for AtCoder Beginner Contest 052 Problems in C++
A – Two Rectangles [Max Area Logic]
Given the dimensions of two rectangles:
Rectangle 1: (A \times B)
Rectangle 2: (C \times D)
Determine and output the larger area. Tie-breaking is irrelevant.
i64 a, b, c, d;
std::cin >> a >> b >> c >> d;
i64 r1 = a * b, r2 = c * d;
i64 best = (r1 >= r2) ? r1 : r2;
std::cout <&l ...
Posted on Sun, 28 Jun 2026 17:59:34 +0000 by Angus
Efficient Submatrix Sum Queries Using Prefix Sums
Problem Statement
Given an n×m integer matrix and q queries, each query specifies the coordinates of the top-left and bottom-right corners of a submatrix. For each query, compute the sum of all elements within the specified submatrix.
Solution Approach
The problem can be efficiently solved using 2D prefix sums. By precomputing the cumulative su ...
Posted on Sun, 28 Jun 2026 17:36:37 +0000 by trufla
Segment Tree Variants and Categorization Techniques
Linear Operation Segment Trees
The most basic form of segment tree handles linear operations that satisfy commutativity and associativity, such as addition. Since operations do not depend on each other, maintaining lazy propagation is straightforward. For single-point modifications, a Fenwick Tree (Binary Indexed Tree) is often a more efficient ...
Posted on Sun, 28 Jun 2026 16:55:59 +0000 by sycoj0ker
Technical Analysis of Xiangtan University Spring 2023 Freshman Programming Contest
Problem A: Strategic Allocation
This challenge involves selecting a subset of items to meet a weight capacity requirement with the minimum count. The optimal approach utilizes a greedy strategy. By prioritizing larger weights first, we minimize the number of items required to reach the target threshold.
void processAllocation() {
int itemCo ...
Posted on Sat, 27 Jun 2026 16:02:21 +0000 by mattpointblank
Solutions for AtCoder Beginner Contest 314 Programming Challenges
Display the first N+2 digits of π (including the decimal point).
#include <iostream>
#include <string>
const std::string PI_DIGITS = "3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679";
int main() {
int digits;
std::cin >> digits;
std::cout << P ...
Posted on Thu, 25 Jun 2026 17:42:23 +0000 by kjtocool
Efficient Range Queries and Updates: Prefix Sums and Difference Arrays
1. Prefix Sum Technique
1.1 One-Dimensional Prefix Sum
The prefix sum algorithm is an optimization technique used to calculate the sum of elements within a specific range $[L, R]$ in $O(1)$ time after an $O(N)$ preprocessing step. In a naive approach, calculating range sums repeatedly would result in $O(N \times M)$ complexity for $M$ queries; ...
Posted on Sun, 21 Jun 2026 17:52:00 +0000 by musicbase
Programming Competition Problem Solutions and Analysis
Mathematical Caclulation Problem
Given the formula for distance between a point and a line, we can simpliyf the calculation to |x-y| * 50:
#include <iostream>
#include <cmath>
int main() {
int x, y;
std::cin >> x >> y;
std::cout << abs(y - x) * 50 << '\n';
return 0;
}
String Output Problem
S ...
Posted on Fri, 19 Jun 2026 18:14:18 +0000 by jantheman
Latin America Regional Programming Contest Solutions: Advanced Algorithm Techniques
Problem D: DiviDuelo
Approach
This problem requires number theory analysis and prime factorization techniques. The solution involves categorizing cases based on the prime factorization of the input number. The implementation uses advanced primality testing and factorization algorithms including Miller-Rabin and Pollard's rho method.
Implementat ...
Posted on Thu, 18 Jun 2026 16:00:43 +0000 by sjaccaud
Efficient Management of Randomized Interval Operations using Chtholly Tree
Introduction
The Chtholly Tree, often referred to as the Old Driver Tree (ODT), is a data structure optimized for specific scenarios involving sequence operations. It is particularly effective when problems feature range assignment operations and randomly generated data. The core principle involves decomposing a sequence into contiguous interva ...
Posted on Tue, 16 Jun 2026 17:50:38 +0000 by jevman
Algorithmic Patterns in Competitive Programming: Segment Reconstruction, Suffix Merge Structures, and Greedy Validity Checks
Segment Reconstruction via Monotonic Stacks and Offline Union-Find
The problem involves optimizing a linear combination of array elements where each coefficient follows a specific growth pattern. Mathematical induction reveals that the optimal coefficient sequence consists of concatenated blocks starting from index one, with internal values dou ...
Posted on Mon, 15 Jun 2026 17:04:09 +0000 by djcubez