Submission #54738

#	Time	Username	Problem	Language	Result	Execution time	Memory
54738		ksun48	Park (JOI17_park)	C++14	20 / 100	653 ms	1056 KiB

park

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

int P[1400];
int ask(int a, int b){
	if(P[a] == 0 || P[b] == 0) return 0;
	if(a == b) return 1;
	return Ask(min(a,b), max(a,b), P);
}
void solve1(int n){
	for(int i = 0; i < n; i++){
		P[i] = 0;
	}
	for(int i = 0; i < n; i++){
		for(int j = i+1; j < n; j++){
			P[i] = P[j] = 1;
			if(ask(i,j)){
				Answer(i, j);
			}
			P[i] = P[j] = 0;
		}
	}
}

int check_edge(int a, int b, int n){
	if(a == b) return 0;
	for(int i = 0; i < n; i++){
		P[i] = 0;
	}
	P[a] = P[b] = 1;
	return ask(a, b);
}

int check_subtree(int a, int b, int c, int n){
	// a-b is an edge, check if x == b or x is in b's side
	for(int i = 0; i < n; i++){
		P[i] = 1;
	}
	P[b] = 0;
	if(ask(a,c)){
		return 0;
	}
	return 1;
}
void solvetree(vector<int> v, int n){
	if(v.size() <= 1) return;
	while(1){
		int a = v[rand() % v.size()];
		int b = v[rand() % v.size()];
		if(a >= b) continue;

		if(!check_edge(a, b, n)){
			continue;
		}
		Answer(a,b);

		vector<int> v1;
		vector<int> v2;

		for(int x : v){
			if(check_subtree(a, b, x, n)){
				v1.push_back(x);
			} else {
				v2.push_back(x);
			}
		}
		solvetree(v1, n);
		solvetree(v2, n);
		assert(v1.size() < v.size() && v2.size() < v.size());
		return;
	}
}

/*void solvetreev(vector<int> v, int n){
	if(v.size() <= 1) return;
	while(1){
		int a = v[rand() % v.size()];
		vector<pair<int, vector<int> > > children;
		for(int x : v){
			if(check_edge(a, x, n)){
				children.push_back({x, vector<int>()});
			}
		}
		for(int x : v){
			if(x == a) continue;
			random_shuffle(children.begin(), children.end());
			for(int i = 0; i < children.size(); i++){
				if(check_subtree(a, children[i].first, x, n)){
					children[i].second.push_back(x);
					break;
				}
			}
		}

	}
}*/


void solve2(int n){
	vector<int> v;
	for(int i = 0; i < n; i++){
		v.push_back(i);
	}
	solvetree(v, n);
}
void Detect(int T, int N) {
	srand(48);
	if(T == 1){
		solve1(N);
	} else if(T >= 2){
		solve2(N);
	}
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 0 / 27
• Subtask 4: 0 / 30
• Subtask 5: 0 / 23