Submission #987347

#	Time	Username	Problem	Language	Result	Execution time	Memory
987347		anonymous321	Senior Postmen (BOI14_postmen)	C++17	55 / 100	572 ms	66564 KiB

postmen

// https://oj.uz/problem/view/BOI14_postmen
#include <bits/stdc++.h>
using namespace std;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n, m;
    cin >> n >> m;
    vector<vector<int>> adj_list (n);
    vector<vector<int>> other_id (n);
    vector<int> active (n, 0);
    for (int i = 0; i < m; i++) {
        int a, b;
        cin >> a >> b;
        other_id[a-1].push_back(adj_list[b-1].size());
        other_id[b-1].push_back(adj_list[a-1].size());
        adj_list[a-1].push_back(b-1);
        adj_list[b-1].push_back(a-1);
    }
    
    stack<int> s {};
    s.push(0);
    vector<int> tour {};
    while (!s.empty()) {
        int v = s.top();
        if (adj_list[v].size() > active[v]) {
            int it = adj_list[v][active[v]];
            int it_id = other_id[v][active[v]];
            other_id[adj_list[it][active[it]]][other_id[it][active[it]]] = it_id;
            swap(adj_list[it][it_id], adj_list[it][active[it]]);
            swap(other_id[it][it_id], other_id[it][active[it]]);
            active[it]++;
            active[v]++;
            s.push(it);
        } else {
            s.pop();
            tour.push_back(v);
        }
    }
    
    vector<bool> in_s (n, false);
    vector<vector<int>> sol {};
    for (int i = 0; i < tour.size(); i++) {
        if (in_s[tour[i]]) {
            vector<int> subtour {tour[i]};
            while (!s.empty() && s.top() != tour[i]) {
                subtour.push_back(s.top());
                in_s[s.top()] = false;
                s.pop();
            }
            sol.push_back(subtour);
        } else {
            in_s[tour[i]] = true;
            s.push(tour[i]);
        }
    }
    
    for (auto& it: sol) {
        for (int& v: it) {
            cout << v+1 << " ";
        }
        cout << "\n";
    }
    return 0;
}

Compilation message (stderr)

postmen.cpp: In function 'int main()':
postmen.cpp:27:32: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type' {aka 'int'} [-Wsign-compare]
   27 |         if (adj_list[v].size() > active[v]) {
postmen.cpp:44:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   44 |     for (int i = 0; i < tour.size(); i++) {
      |                     ~~^~~~~~~~~~~~~

• Subtask 1: 38 / 38
• Subtask 2: 17 / 17
• Subtask 3: 0 / 45