Submission #69901

#	Time	Username	Problem	Language	Result	Execution time	Memory
69901		bnahmad15	Toy Train (IOI17_train)	C++17	0 / 100	1814 ms	1508 KiB

train

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

const int N = 5001;
int n,can[N],is[N],cnt = 0,low[N],tim[N],vis[N];
vector <int> g[N],S,need;

void dfs(int u){
	low[u] = tim[u] = ++cnt;
	vis[u] = 1;
	S.push_back(u);
	for(int i = 0;i<g[u].size();i++){
		int v = g[u][i];
		if(tim[v] == -1){
			dfs(v);
		}
		if(vis[v] == 1){
			low[u] = min(low[u],low[v]);
		}
	}
	if(low[u] == tim[u]){
		while(1){
			int v = S.back();
			vis[v] = -1;
			if(low[v] == 1){
				need.push_back(v);
			}
			S.pop_back();
			if(u == v){
				break;
			}
		}
	}
}
std::vector<int> who_wins(std::vector<int> a, std::vector<int> r, std::vector<int> u, std::vector<int> v) {

	std::vector<int> res;
	n = a.size();
	for(int i = 0;i<n;i++){
		can[i] = 0;
		is[i] = 0;
	}
	for(int i = 0;i<u.size();i++){
		g[u[i]].push_back(v[i]);
	}
	for(int i = 0;i<n;i++)
		is[i] = r[i];
	for(int i = 0;i<n;i++){
		if(r[i] == 1){
			for(int j = 0;j<n;j++){
				low[j] = tim[j] = vis[j] = -1;
			}
			cnt = 0;
			need.clear();
			dfs(i);
			int flag = 0;
			for(int j = 0;j<need.size();j++){
				flag = max(flag,is[need[j]]);
			}
			if(flag == 1){
				for(int j = 0;j<need.size();j++){
					can[need[j]] = true;
				}	
			}
		}
	}
	for(int i = 0;i<n;i++){
		res.push_back(can[i]);
	}
	return res;
}

Compilation message (stderr)

train.cpp: In function 'void dfs(int)':
train.cpp:13:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0;i<g[u].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:44:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0;i<u.size();i++){
                ~^~~~~~~~~
train.cpp:58:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int j = 0;j<need.size();j++){
                  ~^~~~~~~~~~~~
train.cpp:62:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int j = 0;j<need.size();j++){
                   ~^~~~~~~~~~~~

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