Submission #405784

#	Time	Username	Problem	Language	Result	Execution time	Memory
405784		peuch	Toy Train (IOI17_train)	C++17	39 / 100	403 ms	25080 KiB

train

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

const int MAXN = 5e5;

int n;

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

void 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){
	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){
	vector<int> w;
	for(int i = 0; i < r.size(); i++){
		if(!r[i]) continue; 
		for(int j = 0; j < r.size(); 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.push_back(marc[i]);
	return w;
}

vector<int> sub4(std::vector<int> a, std::vector<int> r){
	vector<int> w;
	for(int j = 0; j < r.size(); 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.push_back(!marc[i]);
	return w;
}

void bfs(int ini, vector<int> a){
	marc[ini] = 1;
	bom[ini] = 1;
	for(int i = 0; i < n; i++)
		in[i] = ar[i].size();
	queue<int> fila;
	fila.push(ini);
	while(!fila.empty()){
		int cur = fila.front();
		fila.pop();
		for(int i = 0; i < rev[cur].size(); i++){
			int viz = rev[cur][i];
			if(marc[viz]) continue;
			if(!a[viz]) in[viz]--;
			if(!a[viz] && in[viz] != 0) continue;
			marc[viz] = 1;
			bom[viz] = 1;
			fila.push(viz);
		}
	}
	
}

vector<int> sub5(std::vector<int> a, std::vector<int> r, std::vector<int> u, std::vector<int> v){
	vector<int> w (n, 0);
	int especial;
	for(int i = 0; i < n; i++)
		if(r[i]) especial = i;
	
	bfs(especial, a);
	
	bool orFlag = false;
	bool andFlag = true;
	for(int i = 0; i < ar[especial].size(); i++){
		int viz = ar[especial][i];
		orFlag |= bom[viz];
		andFlag &= bom[viz];
	}
	if(a[especial] && !orFlag) return w;
	if(!a[especial] && !andFlag) return w;
	for(int i = 0; i < n; i++)
		w[i] = bom[i];
	
	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);
	
	flag = true;
	for(int i = 0; i < n; i++)
		flag &= !a[i];
		
	if(flag) return sub4(a, r);
	
	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);
}

Compilation message (stderr)

train.cpp: In function 'bool haveCycle(int, int)':
train.cpp:19:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   19 |  for(int i = 0; i < ar[cur].size(); i++){
      |                 ~~^~~~~~~~~~~~~~~~
train.cpp: In function 'void dfs(int)':
train.cpp:31:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |  for(int i = 0; i < rev[cur].size(); i++){
      |                 ~~^~~~~~~~~~~~~~~~~
train.cpp: In function 'std::vector<int> sub3(std::vector<int>, std::vector<int>)':
train.cpp:65:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   65 |  for(int i = 0; i < r.size(); i++){
      |                 ~~^~~~~~~~~~
train.cpp:67:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   67 |   for(int j = 0; j < r.size(); j++)
      |                  ~~^~~~~~~~~~
train.cpp: In function 'std::vector<int> sub4(std::vector<int>, std::vector<int>)':
train.cpp:82:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   82 |  for(int j = 0; j < r.size(); j++)
      |                 ~~^~~~~~~~~~
train.cpp: In function 'void bfs(int, std::vector<int>)':
train.cpp:109:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  109 |   for(int i = 0; i < rev[cur].size(); i++){
      |                  ~~^~~~~~~~~~~~~~~~~
train.cpp: In function 'std::vector<int> sub5(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>)':
train.cpp:132:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  132 |  for(int i = 0; i < ar[especial].size(); i++){
      |                 ~~^~~~~~~~~~~~~~~~~~~~~
train.cpp: In function 'std::vector<int> who_wins(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>)':
train.cpp:148:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  148 |  for(int i = 0; i < u.size(); i++){
      |                 ~~^~~~~~~~~~
train.cpp: In function 'std::vector<int> sub5(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>)':
train.cpp:137:15: warning: 'especial' may be used uninitialized in this function [-Wmaybe-uninitialized]
  137 |  if(a[especial] && !orFlag) return w;
      |               ^

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