Submission #960004

#	Time	Username	Problem	Language	Result	Execution time	Memory
960004		pcc	Povjerenstvo (COI22_povjerenstvo)	C++17	13 / 100	198 ms	42816 KiB

Main

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

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,popcnt,sse4")

#define pii pair<int,int>
#define fs first
#define sc second
#define ll long long

const int mxn = 5e5+10;

int N,M;
vector<int> paths[mxn];
int deg[mxn];
queue<int> q;
int ans[mxn];
bitset<mxn> done;
vector<int> v;
int col[mxn];
vector<int> bipart[2];

void dfs(int now,int c){
	col[now] = c;
	bipart[col[now]==1].push_back(now);
	for(auto nxt:paths[now]){
		if(done[nxt]||col[nxt])continue;
		dfs(nxt,-c);
	}
}

void psyco(int now){
	bipart[0].clear();bipart[1].clear();
	dfs(now,1);
	bool zcol = true,ocol = true;
	for(auto &i:bipart[0])if(!ans[i])zcol = false;
	for(auto &i:bipart[1])if(!ans[i])ocol = false;
	if(!ocol&&!zcol){
		cout<<-1;
		exit(0);
	}
	if(zcol)for(auto &i:bipart[0])v.push_back(i);
	else for(auto &i:bipart[1])v.push_back(i);
	for(auto &i:bipart[0])done[i] = true;
	for(auto &i:bipart[1])done[i] = true;
	return;
}

int main(){
	ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	cin>>N>>M;
	memset(ans,-1,sizeof(ans));
	for(int i = 1;i<=M;i++){
		int a,b;
		cin>>a>>b;
		deg[a]++;
		paths[b].push_back(a);
	}
	for(int i = 1;i<=N;i++)if(!deg[i])q.push(i);
	while(!q.empty()){
		auto now = q.front();
		done[now] = true;
		q.pop();
		if(ans[now] == -1)ans[now] = 1;
		for(auto nxt:paths[now]){
			deg[nxt]--;
			if(!deg[nxt])q.push(nxt);
			if(ans[now] == 1){
				if(ans[nxt] == -1)ans[nxt] = 0;
			}
		}
	}
	for(int i = 1;i<=N;i++){
		if(ans[i] == 1)v.push_back(i);
	}
	for(int i = 1;i<=N;i++){
		if(!done[i])psyco(i);
	}
	cout<<v.size()<<'\n';
	for(auto &i:v)cout<<i<<' ';cout<<'\n';
	return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:81:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   81 |  for(auto &i:v)cout<<i<<' ';cout<<'\n';
      |  ^~~
Main.cpp:81:29: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   81 |  for(auto &i:v)cout<<i<<' ';cout<<'\n';
      |                             ^~~~

• Subtask 1: 13 / 13
• Subtask 2: 0 / 21
• Subtask 3: 0 / 33
• Subtask 4: 0 / 33