Submission #861261

#	Time	Username	Problem	Language	Result	Execution time	Memory
861261		qwusha	Senior Postmen (BOI14_postmen)	C++17	100 / 100	349 ms	86768 KiB

postmen

#include <bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#pragma gcc optimize("Ofast")
using namespace std;
typedef long long ll;
#define fi first
#define se second
typedef long double ld;
const ll inf = 1e9;
const ld eps = 1e-8;
vector<vector<int>> g;
vector<vector<int>> ans;
vector<bool> used;
vector<int> cur;
vector<int> stcur;
vector<int> res;

struct vert {
    int to;
    bool used;
};

vector<vert> ve;


void add_vert(int v, int u) {
    g[v].push_back(ve.size());
    ve.push_back({u, 0});
    g[u].push_back(ve.size());
    ve.push_back({v, 0});
}



void dfs(int v) {
    if (stcur[v] > 0) {
        res.clear();
        while(cur.back() != v) {
            stcur[cur.back()]--;
            res.push_back(cur.back());
            cur.pop_back();
        }
        stcur[cur.back()]--;
        res.push_back(cur.back());
        cur.pop_back();
        ans.push_back(res);
    }

    while (!g[v].empty()) {
        int e = g[v].back();
        g[v].pop_back();
        if (!ve[e].used) {
            cur.push_back(v);
            stcur[v]++;
            ve[e].used = 1;
            ve[(e ^ 1)].used = 1;
            dfs(ve[e].to);
        }
    }
}



signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    int n, m;
    cin >> n >> m;
    used.resize(n);
    g.resize(n);
    for (int i = 0; i < m; i++) {
        int v, u;
        cin >> v >> u;
        v--;
        u--;
        add_vert(v, u);
    }
    stcur.resize(n);
    dfs(0);
    for (auto s : ans) {
        for (auto el : s) {
            cout << el + 1 << ' ';
        }
        cout << '\n';
    }
}

Compilation message (stderr)

postmen.cpp:4: warning: ignoring '#pragma gcc optimize' [-Wunknown-pragmas]
    4 | #pragma gcc optimize("Ofast")
      |

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