Submission #1226574

#	Time	Username	Problem	Language	Result	Execution time	Memory
1226574		jellybean	Easter Eggs (info1cup17_eastereggs)	C++20	0 / 100	0 ms	492 KiB

eastereggs

#include <bits/stdc++.h>
#include "grader.h"
using namespace std;

#define pb push_back
#define dd(x) cout<<#x<<" is "<<x<<endl;
#define dd2(x,y) cout<<#x<<" is "<<x<<" "<<#y<<" is "<<y<<endl;
#define dl(x) cout<<#x<<" is "<<endl; for(auto i:x) cout<<i<<' '; cout<<endl;
#define fi first
typedef pair<int,int> pii;

vector<int>adj[600];
int par[600],dis[600];
void dfs(int x, int p){
	//par[x] = p;
	for(auto i:adj[x]){
		if(i==p)continue;
		dis[i]=dis[x]+1;
		dfs(i,x);
		
	}
}

void dfs2(int x, int p){
	par[x] = p;
	for(auto i:adj[x]){
		if(i==p)continue;
		dis[i]=dis[x]+1;
		dfs2(i,x);
		
	}
}

int findEgg (int N, vector < pair < int, int > > bridges)
{
    //if (query ({1})) return 1;
    
    int n = N;
    for(int i=1; i<=n; i++){
		adj[i].clear();
	}
	memset(par,0,sizeof(par));
	memset(dis,0,sizeof(dis));
	
    for(int i=0; i<n-1; i++){
		auto[u,v] = bridges[i];
		adj[u].pb(v);
		adj[v].pb(u);
	}
	
	/*int root = -1;
	for(int i=1; i<=n; i++){
		if(adj[i].size() != 1) root = i;
	}*/
	
	dfs(1,-1);
	int root = -1, md = 0;
	for(int i=1; i<=n; i++) if(dis[i] > md) md = dis[i], root=i;
	
	memset(dis,0,sizeof(dis));
	dfs2(root,-1);
	
	md = 0; int root1 = -1;
	for(int i=1; i<=n; i++) if(dis[i] > md) md = dis[i], root1=i;
	
	md/=2;
	for(int i=0; i<md; i++) root1 = par[root1];
	//dd(root1)
	
	queue<int>q;
	vector<int>v;
	
	if (query({root1})) return root1;
	v.pb(root1);
	
	for(auto i: adj[root1]) q.push(i);
	
	while(!q.empty()){
		
		if(q.size() == 1){
			int x = q.front(); q.pop();
			v.pb(x);
			if(query(v)) return x;
			
			for(auto i: adj[x]) if(i!=par[x]) q.push(i);
		}
		else {
			int x = q.front(); q.pop();
			int y = q.front(); q.pop();
			//dd2(x,y)
			
			v.pb(x); v.pb(y);
			if(query(v)){
				if(query({x})) return x;
				else return y;
			}
			
			for(auto i: adj[x]) if(i!=par[x]) q.push(i);
			for(auto i: adj[y]) if(i!=par[y]) q.push(i);
		}
	}
	
    
    return N;
}

• Subtask 1: 0 / 40
• Subtask 2: 0 / 40
• Subtask 3: 0 / 20