Weekly Contest 357 Solutions

Problem 2810 - Faulty Keeyboard Simulate the keyboard behavior as described. When encuontering character 'i', reverse the current string. class Solution { public: string finalString(string input) { string result = ""; for(char c : input) { if(c == 'i') { reverse(result.begin(), ...

Posted on Sun, 10 May 2026 02:00:36 +0000 by stone

Understanding Prüfer Sequences for Labeled Trees

Prüfer sequences are defined only for trees with \(n>1\) vertices. For the case \(n=1\), special handling is required. A Prüfer sequence establishes a bijection between labeled rooted trees on \(n\) vertices and sequences of length \(n-2\) drawn from \([1,n]\cap\Z\). This encoding transforms tree structures into arrays, which proves invaluab ...

Posted on Sat, 09 May 2026 05:15:20 +0000 by dude81

Algorithmic Paradigms and Optimizations in Competitive Programming

Probabilistic Path Enumeration in Directed Acyclic Graphs Given a directed acyclic graph (DAG) consisting of $V$ vertices and $E$ edges, each edge $e_k$ possesses an independent activation probability $p_k$. The objective is to compute the expected number of functional paths originating from vertex $0$ and terminating at vertex $V-1$. A path is ...

Posted on Thu, 07 May 2026 22:27:40 +0000 by PDP11

Contest Solutions: Henan Newbie League 2024 Round 5

A – Calendar Game Ignoring the year, the losing positions follow the pattern (month + day) % 2 == 1, except for the two special dates 9/30 and 11/30 which allow the next player to flip the parity. #include <bits/stdc++.h> using namespace std; int main() { ios::sync_with_stdio(false); cin.tie(nullptr); int t; cin >> t; ...

Posted on Thu, 07 May 2026 16:47:06 +0000 by stuart7398