Submission #906442

#	Time	Username	Problem	Language	Result	Execution time	Memory
906442		pcc	Monthly railway pass (LMIO18_menesinis_bilietas)	C++14	100 / 100	639 ms	116064 KiB

menesinis_bilietas

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

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

const int mxn = 5e5+10;

vector<pii> edges;
int N,M;

bitset<mxn> able;
int dsu[mxn],sz[mxn];
unordered_set<int> paths[mxn];

int root(int k){
	return k == dsu[k]?k:dsu[k] = root(dsu[k]);
}

void onion(int a,int b){
	a = root(a),b = root(b);
	if(a == b)return;
	if(sz[a]<sz[b])swap(a,b);
	dsu[b] = a;
	sz[a] += sz[b];
	return;
}

int main(){
	ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	cin>>N>>M;
	for(int i = 1;i<=N;i++){
		dsu[i] = i,sz[i] = 1;
	}
	for(int i = 0;i<M;i++){
		int a,b;
		char c;
		cin>>a>>b>>c;
		if(c == 'T')onion(a,b);
		else edges.push_back({a,b});
	}
	int gcnt = 0;
	for(auto &i:edges){
		i.fs = root(i.fs);
		i.sc = root(i.sc);
		if(i.fs == i.sc)continue;
		paths[i.fs].insert(i.sc);
		paths[i.sc].insert(i.fs);
	}
	for(int i = 1;i<=N;i++)if(dsu[i] == i)gcnt++;
	for(int i = 1;i<=N;i++){
		if(dsu[i] != i)continue;
		if(paths[i].size()+1 == gcnt)able[i] = true;
	}
	int ans = 0;
	for(int i = 1;i<=N;i++)if(able[root(i)])ans++;
	cout<<ans;
}

Compilation message (stderr)

menesinis_bilietas.cpp: In function 'int main()':
menesinis_bilietas.cpp:57:24: warning: comparison of integer expressions of different signedness: 'std::unordered_set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   57 |   if(paths[i].size()+1 == gcnt)able[i] = true;
      |      ~~~~~~~~~~~~~~~~~~^~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 6 / 6
• Subtask 3: 30 / 30
• Subtask 4: 35 / 35
• Subtask 5: 19 / 19