Submission #980751

#	Time	Username	Problem	Language	Result	Execution time	Memory
980751		Zicrus	Senior Postmen (BOI14_postmen)	C++17	55 / 100	514 ms	41520 KiB

postmen

#include <bits/stdc++.h>
using namespace std;

int n, m, u, v;
vector<pair<int, int>> adj[500000];
vector<int> res;

bool sus[500000];

int main() {
    cin >> n >> m;
    vector<int> deg(n);
    int g = 0;
    for (int i = 0; i < m; i++) {
        cin >> u >> v;
        adj[u-1].push_back({v-1, g});
        adj[v-1].push_back({u-1, g++});
    }

    stack<int> stk;
    stk.push(0);
    while (!stk.empty()) {
        start:
        int s = stk.top();
        while (!adj[s].empty()) {
            int e = adj[s].back().first;
            int i = adj[s].back().second;
            adj[s].pop_back();
            if (!sus[i]) { sus[i] = true; stk.push(e); goto start; }
            else sus[i] = true;
        }
        res.push_back(s);
        stk.pop();
    }

    reverse(res.begin(), res.end());
    vector<int> vst(n, -1);
    vector<int> nxt(n, -1);
    for (int i = 0; i < res.size(); i++) {
        int node = res[i];
        if (vst[node] == -1) {
            vst[node] = i;
            nxt[node] = res[i+1];
        }
        else {
            int nd = res[vst[node]];
            do {
                cout << nd+1 << ' ';
                vst[nd] = -1;
                nd = nxt[nd];
            } while (nd != node);
            cout << '\n';
            nxt[node] = res[i+1];
            vst[node] = i;
        }
    }
}

Compilation message (stderr)

postmen.cpp: In function 'int main()':
postmen.cpp:39:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |     for (int i = 0; i < res.size(); i++) {
      |                     ~~^~~~~~~~~~~~

• Subtask 1: 38 / 38
• Subtask 2: 17 / 17
• Subtask 3: 0 / 45