The first three questions this time...

$$$\Huge\text{ABC376 RP++!}$$$

Good Luck & Have Fun!

What's wrong with my code for D ???

//Author:RasShalGul
#include <bits/stdc++.h>
#define int long long
using namespace std;
int find_minimum_cycle(int N,int M,vector<pair<int,int>>&edges){
	vector<vector<int>>graph(N+1);
	for(const auto& edge:edges){
		graph[edge.first].push_back(edge.second);
	}
	vector<int>dist(N+1,-1);
	vector<int>parent(N+1,-1);
	queue<int>q;
	q.push(1);
	dist[1]=0;
	int min_cycle_length=LONG_LONG_MAX;
	while(!q.empty()){
		int u=q.front();
		q.pop();
		for(int v:graph[u]){
			if(dist[v]==-1){
				dist[v]=dist[u]+1;
				parent[v]=u;
				q.push(v);
			}else if(v!=parent[u]){
				min_cycle_length=min(min_cycle_length,dist[u]+dist[v]+1);
			}
		}
	}
	return (min_cycle_length==LONG_LONG_MAX)?-1:min_cycle_length;
}
signed main(){
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
	cout.tie(nullptr);
	int N,M;
	cin>>N>>M;
	vector<pair<int,int>>edges(M);
	for(int i=0;i<M;i++){
		cin>>edges[i].first>>edges[i].second;
	}
	int result=find_minimum_cycle(N,M,edges);
	cout<<result<<"\n";
	return 0;
}

F is a nice problem, thanks.

G is the answer of https://onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=247&page=show_problem&problem=3646 divides $$$\sum_{i}a_i$$$.

WHAT are you doing,Mr.Atcoder?

Hii,

Did anyone tried to solve D with dfs for cycle detection in directed graph?I tried but it is failing for half of the test cases.I know it is not efficient solution but just wanted to find the case where it can fail

Link to my submission

Thanks

How to solve D if the graph was undirected?

It would be nice to have a separate leaderboard for rated/unrated participants similar to what Codeforces has with a checkbox "show unofficial".

snuke Do you know if a single leaderboard is intentional or there're plans to implement something similar to what I've described?

In problem D. How could more than a cycle contain the same vertex if the vertices each have a single outgoing edge? At least that's what I interpreted by the problem statement

Why is this the initialization of the dp in problem F?

int ph = 0, pp = 0;
dp.assign(Q + 1, vector<int>(N, INF));
dp[0][1] = 0;

This assumes that the other hand is at position 1, but it could be at 0, shouldn't it depend on the first query?