제출 #639590

#제출 시각아이디문제언어결과실행 시간메모리
639590LeticiaFCSMonthly railway pass (LMIO18_menesinis_bilietas)C++17
100 / 100
1224 ms81320 KiB
#include "bits/stdc++.h"
#define st first
#define nd second
using lint = int64_t;
constexpr int MOD = int(1e9) + 7;
constexpr int INF = 0x3f3f3f3f;
constexpr int NINF = 0xcfcfcfcf;
constexpr lint LINF = 0x3f3f3f3f3f3f3f3f;
const long double PI = acosl(-1.0);
// Returns -1 if a < b, 0 if a = b and 1 if a > b.
int cmp_double(double a, double b = 0, double eps = 1e-9) {
	return a + eps > b ? b + eps > a ? 0 : 1 : -1;
}
using namespace std;
struct UF {
	vector<int> e, sz;
	UF(int n) : e(n, -1) {}
	bool same_set(int a, int b) { return find(a) == find(b); }
	int size(int x) { return -e[find(x)]; }
	int find(int x) { return e[x] < 0 ? x : e[x] = find(e[x]); }
	bool unite(int a, int b) {
		a = find(a), b = find(b);
		if (a == b) return 0;
		if (e[a] > e[b]) swap(a, b);
		e[a] += e[b]; e[b] = a;
		return 1;
	}
};

int main() {
	cin.tie(nullptr)->sync_with_stdio(false);
	//int __; cin >> __; for( int _ = 1 ; _ <= __ ; _++ ){ }
	int n, m;
	cin>>n>>m;
	using pii = pair<int, int>;
	vector<pii> bus;
	
	UF uf(n);
	
	while(m--){
		int u, v;
		cin>>u>>v;
		u--, v--;
		string type;
		cin>>type;
		if(type == "A"){
			bus.emplace_back(u, v);
		} else {
			uf.unite(u, v);	
		}
	}
	
	map<int, int> compr;
	
	int id = 0;
	for(int u=0; u<n; u++)
		if(!compr.count(uf.find(u)))
			compr[uf.find(u)] = id++;
	
	vector<set<int>> cg(id);
	for(auto &[u, v]: bus){
		u = uf.find(u);
		v = uf.find(v);
		if(u != v){
			cg[compr[u]].insert(compr[v]);
			cg[compr[v]].insert(compr[u]);
		}
	}
	int answer = 0;
	for(auto &[u, c]: compr)
		if((int) cg[c].size() == id-1)
			answer += uf.size(u);
	cout<<answer<<"\n";
	
	return 0;
}
/*
[  ]Leu o problema certo???
[  ]Ver se precisa de long long
[  ]Viu o limite dos fors (é n? é m?)
[  ]Tamanho do vetor, será que é 2e5 em vez de 1e5??
[  ]Testar sample
[  ]Testar casos de  borda
[  ]1LL no 1LL << i
[  ]Testar mod (é 1e9+7, mesmo?, será que o mod não ficou negativo?)
*/
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