Submission #405762

#	Time	Username	Problem	Language	Result	Execution time	Memory
405762		peuch	Toy Train (IOI17_train)	C++17	0 / 100	155 ms	3232 KiB

train

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

const int MAXN = 5e3 + 10;

int n;

int marc[MAXN];
int pode[MAXN];
int	bom[MAXN];

vector<int> ar[MAXN];
vector<int> rev[MAXN];

bool haveCycle(int cur, int ori){
	marc[cur] = 1;
	for(int i = 0; i < ar[cur].size(); i++){
		int viz = ar[cur][i];
		if(viz == ori) return true; 
		if(marc[viz]) continue;
		if(pode[viz]) continue;
		if(haveCycle(viz, ori)) return true;
	}
	return false;
}

bool dfs(int cur){
	marc[cur] = 1;
	for(int i = 0; i < rev[cur].size(); i++){
		int viz = rev[cur][i];
		if(marc[viz]) continue;
		dfs(viz);
	}
}

vector<int> sub1(std::vector<int> a, std::vector<int> r, std::vector<int> u, std::vector<int> v){
	vector<int> w(n, 0);
	for(int i = n - 1; i >= 0; i--){
		if(ar[i].size() == 2){
			if(a[i]){
				if(r[i]) w[i] = 1;
				else w[i] = w[i + 1];
			}
			else{
				if(r[i]) w[i] = w[i + 1];
				else w[i] = 0;
			}
		}
		else if(ar[i][0] == i) w[i] = r[i];
		else w[i] = w[i + 1];
	}
	return w;
}


vector<int> sub2(std::vector<int> a, std::vector<int> r, std::vector<int> u, std::vector<int> v){
	vector<int> w(n, 0);
	return w;
}

vector<int> sub3(std::vector<int> a, std::vector<int> r, std::vector<int> u, std::vector<int> v){
	vector<int> w(n, 0);
	for(int i = 0; i < n; i++){
		if(!r[i]) continue; 
		for(int j = 0; j < n; j++)
			marc[j] = 0;
		bom[i] = haveCycle(i, i);
	}
	for(int j = 0; j < n; j++)
		marc[j] = 0;
	for(int i = 0; i < n; i++)
		if(bom[i]) dfs(i);
	for(int i = 0; i < n; i++)
		w[i] = marc[i];
	return w;
}

vector<int> sub4(std::vector<int> a, std::vector<int> r, std::vector<int> u, std::vector<int> v){
	vector<int> w(n, 0);
	for(int j = 0; j < n; j++)
		pode[j] = r[j];
	for(int i = 0; i < n; i++){
		if(r[i]) continue;
		for(int j = 0; j < n; j++)
			marc[j] = 0;
		bom[i] = haveCycle(i, i);
	}
	for(int j = 0; j < n; j++)
		marc[j] = 0;
	for(int i = 0; i < n; i++)
		if(bom[i]) dfs(i);
	for(int i = 0; i < n; i++)
		w[i] = !marc[i];
	return w;
}

vector<int> sub5(std::vector<int> a, std::vector<int> r, std::vector<int> u, std::vector<int> v){
	vector<int> w(n, 0);
	return w;
}

std::vector<int> who_wins(std::vector<int> a, std::vector<int> r, std::vector<int> u, std::vector<int> v) {
	n = a.size();
	
	for(int i = 0; i < u.size(); i++){
		ar[u[i]].push_back(v[i]);
		rev[v[i]].push_back(u[i]);
	}
	
//	if(n <= 15) return sub2(a, r, u, v); 
	
	bool flag = true;
	for(int i = 0; i < n; i++)
		flag &= a[i];
		
	if(flag) return sub3(a, r, u, v);
	
	flag = true;
	for(int i = 0; i < n; i++)
		flag &= !a[i];
		
	if(flag) return sub4(a, r, u, v);
	
	int cnt = 0;
	
	for(int i = 0; i < n; i++)
		cnt += r[i];
	
//	if(cnt == 1) return sub5(a, r, u, v);
	
	return sub1(a, r, u, v);
}

Compilation message (stderr)

train.cpp: In function 'bool haveCycle(int, int)':
train.cpp:18:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   18 |  for(int i = 0; i < ar[cur].size(); i++){
      |                 ~~^~~~~~~~~~~~~~~~
train.cpp: In function 'bool dfs(int)':
train.cpp:30:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |  for(int i = 0; i < rev[cur].size(); i++){
      |                 ~~^~~~~~~~~~~~~~~~~
train.cpp:35:1: warning: no return statement in function returning non-void [-Wreturn-type]
   35 | }
      | ^
train.cpp: In function 'std::vector<int> who_wins(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>)':
train.cpp:106:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  106 |  for(int i = 0; i < u.size(); i++){
      |                 ~~^~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 10
• Subtask 3: 0 / 11
• Subtask 4: 0 / 11
• Subtask 5: 0 / 12
• Subtask 6: 0 / 51