Submission #1119658

#	Time	Username	Problem	Language	Result	Execution time	Memory
1119658		vjudge1	Senior Postmen (BOI14_postmen)	C++17	100 / 100	469 ms	67688 KiB

postmen

#include<bits/stdc++.h>
#define int long long
#define ii pair < int , int >
#define iii pair < int , ii >
#define iv pair < ii , ii >
#define fi first
#define se second
#define task "senior_postmen"
using namespace std;
const int N = 5e5 + 5;
const int mod = 998244353;

int n, m;
vector< ii > g[N];
bool used_edge[N];
bool vis[N], del[N];

list<int> euler_walk(int u) {
    list<int> ans;

    ans.push_back(u);

    while (!g[u].empty()) {
        int v = g[u].back().fi;
        int eid = g[u].back().se;

        g[u].pop_back();

        if (used_edge[eid]) continue;

        used_edge[eid] = true;

        u = v;
        ans.push_back(u);
    }

    for (auto it = ++ans.begin(); it != ans.end(); ++it) {
        auto t = euler_walk(*it);

        t.pop_back();
        ans.splice(it, t);
    }

    return ans;
}


main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    if (fopen(task".inp", "r")){
        freopen(task".inp", "r", stdin);
//        freopen(task".out", "w", stdout);
    }

    cin >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        int u, v; cin >> u >> v;
        g[u].push_back(ii(v, i));
        g[v].push_back(ii(u, i));
    }

    list < int > ct_euler = euler_walk(1);
//    for(auto x : ct_euler) cout << x << " "; cout << endl;
    stack < int > st;
    for(auto x : ct_euler){
        if(vis[x]){
            while(!st.empty()){
                int v = st.top();
                cout << v << " ";
                vis[v] = 0;
                st.pop();
                if(v == x) break;
            }
            cout << '\n';
        }
        st.push(x);
        vis[x] = 1;
    }
}

Compilation message (stderr)

postmen.cpp:48:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   48 | main()
      | ^~~~
postmen.cpp: In function 'int main()':
postmen.cpp:54:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   54 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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