Submission #987700

#	Time	Username	Problem	Language	Result	Execution time	Memory
987700		anonymous321	Senior Postmen (BOI14_postmen)	C++17	55 / 100	631 ms	93800 KiB

postmen

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

vector<vector<int>> adj_list;
vector<vector<int>> other_id;
vector<int> active;
vector<int> tour {};

void hhz (int v) {
    while (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]++;
        hhz(it);
    }
    tour.push_back(v);
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n, m;
    scanf("%d %d", &n, &m);
    adj_list = vector<vector<int>>(n);
    other_id = vector<vector<int>>(n);
    active = vector<int>(n, 0);
    for (int i = 0; i < m; i++) {
        int a, b;
        scanf("%d %d", &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);
    }

    hhz(0);
    
    stack<int> s {};
    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) {
            printf("%d ", v+1);
        }
        printf("\n");
    }
    return 0;
}

Compilation message (stderr)

postmen.cpp: In function 'void hhz(int)':
postmen.cpp:11:31: 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]
   11 |     while (adj_list[v].size() > active[v]) {
postmen.cpp: In function 'int main()':
postmen.cpp:46:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   46 |     for (int i = 0; i < tour.size(); i++) {
      |                     ~~^~~~~~~~~~~~~
postmen.cpp:28:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   28 |     scanf("%d %d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~~
postmen.cpp:34:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   34 |         scanf("%d %d", &a, &b);
      |         ~~~~~^~~~~~~~~~~~~~~~~

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