Submission #961921

#	Time	Username	Problem	Language	Result	Execution time	Memory
961921		Irate	Monthly railway pass (LMIO18_menesinis_bilietas)	C++17	100 / 100	314 ms	51768 KiB

menesinis_bilietas

#include <bits/stdc++.h>
using namespace std;
const int mxN = 5e5 + 5;
struct DSU{
    vector<int>par;
    int comps;
    DSU(int n){
        par.assign(n + 1, -1);
        comps = n;
    }
    int FindRep(int u){
        if(par[u] < 0)return u;
        return par[u] = FindRep(par[u]);
    }
    void Union(int u, int v){
        u = FindRep(u);
        v = FindRep(v);
        if(u == v)return;
        if(par[u] > par[v])swap(u, v);
        par[u] += par[v];
        par[v] = u;
        comps--;
    }
};
struct T{
    int u, v;
    char c;
};
vector<int> G[mxN];
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int n, m;
    cin >> n >> m;
    /// A - bus, T - train
    vector<T>edges(m);
    DSU dsu(n);
    for(int i = 0;i < m;++i){
        int u, v;
        char c;
        cin >> u >> v >> c;
        edges[i] = {u, v, c};
        if(c == 'T')dsu.Union(u, v);
    }
    set<pair<int, int>>s;
    for(int i = 0;i < m;++i){
        int u = dsu.FindRep(edges[i].u), v = dsu.FindRep(edges[i].v), c = edges[i].c;
        if(c == 'T' || u == v)continue;
        s.insert({u, v});
    }
    for(auto i : s){
        int u = i.first, v = i.second;
        G[u].push_back(v);
        G[v].push_back(u);
    }
    int res = 0, comps = dsu.comps;
    for(int i = 1;i <= n;++i){
        int u = dsu.FindRep(i);
        res += ((int)G[u].size() == comps - 1);
    }
    cout << res << '\n';
}

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