Submission #1150486

#	Time	Username	Problem	Language	Result	Execution time	Memory
1150486		The_Samurai	Senior Postmen (BOI14_postmen)	C++20	100 / 100	193 ms	68472 KiB

postmen

// I stand with PALESTINE
 
 
 
 
// #pragma GCC optimize("Ofast,O3")
// #pragma GCC target("avx,avx2")
#include "bits/stdc++.h"
 
using namespace std;
using ll = long long;
 
const int M = 5e5 + 5, N = 5e5 + 5;
 
vector<bool> deleted(M);
vector<vector<pair<int, int>>> g(N);
vector<int> way;
 
void dfs(int u) {
    while (!g[u].empty()) {
        if (deleted[g[u].back().second]) {
            g[u].pop_back();
            continue;
        }
        deleted[g[u].back().second] = true;
        dfs(g[u].back().first);
    }
    way.emplace_back(u);
}
 
void solve() {
    int n, m;
    cin >> n >> m;
    for (int i = 0; i < m; i++) {
        int u, v;
        cin >> u >> v;
        g[u].emplace_back(v, i);
        g[v].emplace_back(u, i);
    }
    for (int i = 1; i <= n; i++) {
        if (g[i].size() % 2) assert(false);
    }
    dfs(1);
    if (way.size() < m + 1) assert(false);
    vector<int> last(n + 1, -1), vec;
    // for (int &x: way) cout << x << ' ';
    // cout << endl;
    for (int i = 0; i < way.size(); i++) {
        vec.emplace_back(way[i]);
        // cout << way[i] << ' ' << last[way[i]] << endl;
        if (last[way[i]] != -1) {
            cout << vec.back() << ' ';
            vec.pop_back();
            while (vec.back() != way[i]) {
                last[vec.back()] = -1;
                cout << vec.back() << ' ';
                vec.pop_back();
            }
            cout << '\n';
        } else {
            last[way[i]] = i;
        }
    }
}
 
int main() {
    cin.tie(0)->sync_with_stdio(false);
#ifdef sunnatov
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif
    int q = 1;
    // cin >> q;
    while (q--) {
        solve();
        // cout << '\n';
    }
}

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