Submission #687337

#	Time	Username	Problem	Language	Result	Execution time	Memory
687337		Do_you_copy	Senior Postmen (BOI14_postmen)	C++17	100 / 100	441 ms	61876 KiB

postmen

//Then
#include <bits/stdc++.h>
#define pb push_back
#define fi first
#define se second
#define faster ios_base::sync_with_stdio(0); cin.tie(0);

using namespace std;
using ll = long long;
using ld = long double;
using pii = pair <int, int>;
mt19937_64 Rand(chrono::steady_clock::now().time_since_epoch().count());
const int maxN = 1e6 + 1;
//const int Mod = 1e9 + 7;
//const int inf =
int n, m;

struct TEdge{
    int u, v;
    bool del;
};

TEdge e[maxN];
vector <int> adj[maxN];

bool visited[maxN];

void Init(){
    cin >> n >> m;
    for (int i = 1; i <= m; ++i){
        int u, v;
        cin >> u >> v;
        e[i] = {u, v, 0};
        adj[u].pb(i);
        adj[v].pb(i);
    }
    vector <int> eulertour;
    vector <int> S(1, 1);
    while (!S.empty()){
        int u = S.back();
        while (!adj[u].empty() && e[adj[u].back()].del) adj[u].pop_back();
        if (!adj[u].empty()){
            auto &i = e[adj[u].back()];
            S.pb(i.u ^ i.v ^ u);
            i.del = 1;
            adj[u].pop_back();
        }
        else{
            eulertour.pb(u);
            S.pop_back();
        }
    }
    vector <int> ans;
    for (int u: eulertour){
        if (visited[u]){
            int v;
            do{
                v = ans.back();
                visited[v] = 0;
                cout << v << " ";
                ans.pop_back();
            } while (v != u);
            cout << "\n";
        }
        ans.pb(u);
        visited[u] = 1;
    }
}

#define debug
#define taskname "test"
signed main(){
    faster
    if (fopen(taskname".inp", "r")){
        freopen(taskname".inp", "r", stdin);
        freopen(taskname".out", "w", stdout);
    }
    int tt = 1;
    //cin >> tt;
    while (tt--){
        Init();
    }
    if (fopen("timeout.txt", "r")){
        ofstream timeout("timeout.txt");
        timeout << signed(double(clock()) / CLOCKS_PER_SEC * 1000);
        timeout.close();
        #ifndef debug
        cerr << "Time elapsed: " << signed(double(clock()) / CLOCKS_PER_SEC * 1000) << "ms\n";
        #endif // debug
    }
}

Compilation message (stderr)

postmen.cpp: In function 'int main()':
postmen.cpp:75:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   75 |         freopen(taskname".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
postmen.cpp:76:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   76 |         freopen(taskname".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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