Cod sursa(job #2646658)

Utilizator DormeoNoapte Buna Dormeo Data 1 septembrie 2020 17:18:59
Problema Ciclu Eulerian Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.04 kb
#include <bits/stdc++.h>

using namespace std;

ifstream fin ("ciclueuler.in");
ofstream fout ("ciclueuler.out");

const int DIM = 100000 + 5;

list < int > a[DIM];
stack < int > st;
vector < int > sol;

int main()
{
    int n, m;

    fin >> n >> m;
    for(int i = 1; i <= m; ++i) {
        int x, y;

        fin >> x >> y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    for(int i = 1; i <= n; ++i) {
        if(a[i].size() % 2 == 1 || a[i].size() == 0) {
            fout << "-1" << "\n";
            return 0;
        }
    }
    st.push(1);
    while(!st.empty()) {
        int k = st.top();
        if(a[k].size() > 0) {
            int v = *a[k].begin();
            list < int > ::iterator it = find(a[v].begin(), a[v].end(), k);
            a[v].erase(it);
            a[k].erase(a[k].begin());
            st.push(v);
        }
        else {
            st.pop();
            sol.push_back(k);
        }
    }
    sol.pop_back();
    for(auto v : sol) fout << v << " ";
    return 0;
}