Given three values A, B, and C where A < B < C, if A + B < C, no valid solution exists; otherwise, the answer is simply C. For the second problem, consider an N×N grid filled with numbers from 1 to N². The task is to count configurations where no row minimum equals any column maximum. Defin...
Maximizing Triples Product Given three integers, you can increment any of them exactly five times. The goal is to maximize their final product. To achieve the maximum product, we should always increment the smallest of the three integers. This minimizes the disparity between the values, which yields...
After everyone else in the computer lab had many orange-rated handles, I finally achieved orange with my main account (apparently, I'm still quite weak). I'll write a blog post to record the experience. My counting skills are very poor. In the last 5 minutes of the contest, I hastily came up with a...
Problem 1: Apple Planting Problem Description There is an n-row by m-column farmland in front of Taotao's house. Some grids can grow apples (represented by 1), while others cannot (represented by 0). Additionally, adjacent grids cannot both grow apples. Taotao wants to know how many possible plantin...
Merging Strings for Maximum Palindromes Given two strings $S1$ and $S2$, we aim to merge them into a single string $S3$ while maintaining the relative order of characters from the original strings. The goal is to find the maximum possible length of a palindromic substring within any such $S3$. A fou...
You are given an array of integers. Find the maximum possible product of five elements from the array, where the indices of these elements are in strictly increasing order. Input The input consists of multiple test cases. The first line contains an enteger t (1 ≤ t ≤ 2 × 10^4) — the number of test c...
Identifying Problems Suitable for Binary Search Binary search is applicable to optimization problems with these common features: Finding the minimum possible maximum value (or maximum possible minimum value) Determining the maximum or minimum value of a variable If we denote the target value as targ...
Introduction This article presents a curated selection of problems from various AtCoder Regular Contest (ARC) editions. Each problem is analyzed and rewritten to preserve the core concepts while reducing similarity to the original content. The focus is on problem-solving techniques, algorithmic appr...
Power Decomposition Given an integer n, output its representation as a sum of distinct powers of two in descending order, or -1 if n is odd. #include <iostream> using namespace std; int main() { int val; cin >> val; if (val % 2 != 0) { cout << "-1"; return 0; } for (int e...
Dynamic Segment Tree Merging Combining two dynamically allocated segment trees enables efficient aggregation of information across disjoint sets or hierarchical structures. The operation recursively merges corresponding nodes from both trees. When one subtree is empty, the non-empty counterpart is r...