Submission #920877

#	Time	Username	Problem	Language	Result	Execution time	Memory
920877		itslq	Monthly railway pass (LMIO18_menesinis_bilietas)	C++17	100 / 100	566 ms	159824 KiB

menesinis_bilietas

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

vector<int> pa, rk;

int getParent(int n) {
    if (pa[n] == n) return n;
    return pa[n] = getParent(pa[n]);
}

void mge(int x, int y) {
    if (x == y) return;

    if (rk[x] > rk[y]) {
        pa[y] = x;
    } else if (rk[x] == rk[y]) {
        pa[y] = x;
        rk[x]++;
    } else {
        pa[x] = y;
    }
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    int N, M, A, B, x, y;
    char T;
    cin >> N >> M;

    pa.resize(N);
    rk.resize(N);
    for (int i = 0; i < N; i++) pa[i] = i;
    fill(rk.begin(), rk.end(), 0);

    unordered_map<int, unordered_set<int>> busadj;
    vector<pair<int, int>> bus;
    vector<int> ch[N];

    while (M--) {
        cin >> A >> B >> T;
        A--; B--;

        if (T == 'T') {
            mge(getParent(A), getParent(B));
        } else {
            bus.push_back(make_pair(A, B));
        }
    }

    for (int i = 0; i < N; i++) {
        x = getParent(i);
        ch[x].push_back(i);
        if (ch[x].size() == N) {
            cout << N;
            return 0;
        }
    }

    for (pair<int, int> route: bus) {
        x = getParent(route.first);
        y = getParent(route.second);

        if (x == y) continue;

        busadj[x].insert(y);
        busadj[y].insert(x);
    }

    int C = 0;

    for (pair<int, unordered_set<int>> station: busadj) {
        if (station.second.size() + 1 == busadj.size()) {
            C += ch[station.first].size();
        }
    }

    cout << C;
    return 0;
}

Compilation message (stderr)

menesinis_bilietas.cpp: In function 'int main()':
menesinis_bilietas.cpp:58:26: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   58 |         if (ch[x].size() == N) {
      |             ~~~~~~~~~~~~~^~~~

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