Submission #1045640

#	Time	Username	Problem	Language	Result	Execution time	Memory
1045640		pcc	Toy Train (IOI17_train)	C++17	11 / 100	1125 ms	4436 KiB

train

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

const int mxn = 5050;

vector<int> charge;
int N,M;
queue<int> q;
int owner[mxn];
bitset<mxn> reach[mxn],dist;
vector<int> paths[mxn];
bitset<mxn> ban;
bitset<mxn> cyc;

void BFS(int s = -1){
	if(s != -1){
		dist.reset();
		q.push(s);
	}
	while(!q.empty()){
		auto now = q.front();
		q.pop();
		for(auto nxt:paths[now]){
			if(!dist[nxt]&&!ban[nxt]){
				dist[nxt] = 1;
				q.push(nxt);
			}
		}
	}
	return;
}

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<N;i++){
		owner[i] = a[i];
		if(r[i]){
			charge.push_back(i);
		}
	}
	for(int i = 0;i<u.size();i++){
		int aa = u[i],bb = v[i];
		paths[aa].push_back(bb);
	}
	for(int i = 0;i<N;i++){
		BFS(i);
		reach[i] = dist;
	}
	for(auto &i:charge)ban[i] = true;
	for(int i = 0;i<N;i++){
		BFS(i);
		cyc[i] = dist[i];
	}
	/*
	cerr<<"CYC:";for(int i = 0;i<N;i++)cerr<<cyc[i];cerr<<endl;
	cerr<<"BAN:";for(int i = 0;i<N;i++)cerr<<ban[i];cerr<<endl;
	*/
	vector<int> ans(N,1);
	for(int i = 0;i<N;i++){
		for(int j = 0;j<N;j++){
			if(reach[i][j]&&cyc[j])ans[i] = 0;
		}
	}
	return ans;
}

Compilation message (stderr)

train.cpp: In function 'std::vector<int> who_wins(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>)':
train.cpp:42:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |  for(int i = 0;i<u.size();i++){
      |                ~^~~~~~~~~

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