Algorithmic Solutions for Competitive Programming Problems
1. Resource Allocation using Binary Search
This problem requires determining the minimum capacity needed to partition a set of resources into a specific number of groups. A binary search approach is suitable here. The goal is to find the smallest value x such that the items can be covered by at most k groups, where each group has a capacity lim ...
Posted on Wed, 05 Aug 2026 16:39:25 +0000 by brianbehrens
Codeforces Round 165 Editorial - Problem Analysis
Problem A: Two Friends
There are two possible scenarios:
There exists a pair where person A's best friend is B, and B's best friend is A. In this case, just inviting these two individuals suffices.
No such mutual friendship exists. If person A's best friend is B, and B's best friend is C, then inviting A, B, and C ensures both A and B attend.
...
Posted on Sat, 01 Aug 2026 17:04:36 +0000 by penguinmasta
Essential 2D Array Algorithms for Competitive Programming
Matrix Rotation Techniques
Matrix rotation involves reorganizing elements in a square grid through geometric transformations. The fundamental approach combines transposition with selective reversal operations.
Clockwise 90-Degree Rotation
The process involves two sequential transformations: first transpose the matrix, then reverse each row hori ...
Posted on Sat, 01 Aug 2026 16:32:16 +0000 by slipmatt2002
Solutions for Codeforces Round 899 Division 2 Problems
Problem A: Minimum Non-Conflicting Value Sequence
Given a sequence of intgeers, find the smallest positive integer that can be added to make all elements distinct while maintaining increasing order.
#include<iostream>
#include<vector>
using namespace std;
int find_min_increment(vector<int>& nums) {
int current = 1;
...
Posted on Sat, 01 Aug 2026 16:13:35 +0000 by chaffinator
Algorithmic Breakdown of AtCoder Beginner Contest 063 Problems
Problem A: Threshold Validation
Statement: Evaluate the summation of two integer inputs. Return the calculated value if it remains within or below ten; otherwise, flag an invalid state.
Approach: Direct arithmetic comparison eliminates the need for complex graph algorithms. Computing the aggregate and applying a single conditional branch yields ...
Posted on Sat, 25 Jul 2026 16:40:08 +0000 by TeamTJ
Dynamic Programming Solutions for Competitive Programming Problems
Potion-making Solution
This problem requires solving the equation i/(i+j) = k/100 to find the minimal total ingredients. The solution involves iterating through possiblle values of i and j.
#include <iostream>
#include <cmath>
using namespace std;
void solvePotion() {
int target_percentage;
cin >> target_percentage;
...
Posted on Mon, 20 Jul 2026 17:27:42 +0000 by pod2oo5
Fundamental Algorithmic Patterns and Code Templates for Competitive Programming
Binary Search Methodologies
Integer binary search typically relies on partitioning a range [left, right] based on a predicate function. Two common partitions are used depending on whether the midpoint belongs to the left or right sub-interval.
// Partition: [left, pivot] | [pivot + 1, right]
int find_first_valid(int left, int right) {
while ...
Posted on Sat, 18 Jul 2026 16:57:35 +0000 by kmutz22
Efficient Solution for Two-Interval Sum Problem Using Two-Pointer Technique
Problem AnalysisThe problem requires finding, for each position i in an array, the maximum value k such that the sum of elements in the left interval [i, i+k-1] and the sum of elements in the right interval [i+k, i+2*k-1] are both less than or equal to a given value s.Why Binary Search FailsAt first glance, one might consider using binary searc ...
Posted on Thu, 16 Jul 2026 17:10:43 +0000 by flattened
AtCoder Beginner Contest 352 Solutions
Problem A - AtCoder Line Straightforward check: determine whether point z lies between x and y on the number line. Simply swap if necessary to ansure x ≤ y, then verify the condition. Click to view code
#include <cstdio>
#include <algorithm>
using namespace std;
int main()
{
int n, p, q, r;
scanf("%d%d%d%d", & ...
Posted on Thu, 16 Jul 2026 17:03:34 +0000 by craigbabe
AtCoder Beginner Contest 014 - Problem Solutions
Problem A
Given a snacks to distribute equally among b people. Snacks cannot be divided. Find the minimum number of additional snacks that need to be purchased.
Solution
Each person requires ceil(a/b) snacks. Therefore, the total snacks needed is ceil(a/b) * b. The additional snacks required is ceil(a/b) * b - a.
int snacks, people;
std::cin &g ...
Posted on Tue, 14 Jul 2026 17:33:54 +0000 by ypkumar