Submission #419661

#	Time	Username	Problem	Language	Result	Execution time	Memory
419661		VladM	Senior Postmen (BOI14_postmen)	C++17	55 / 100	550 ms	125024 KiB

postmen

#include <bits/stdc++.h>

using namespace std;

#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")

int u, v, n, m;

vector<int> par, vis;

vector<set<int> > vec;

void dfs(int v)
{
    vis[v]=1;
    int p=0;
    for(auto to : vec[v])
    {
        if(to==par[v]) continue;
        if(vis[to]==1)
        {
            vec[v].erase(to);
            vec[to].erase(v);
            while(v!=to)
            {
                p=par[v];
                printf("%d ", v);
                vec[v].erase(p);
                vec[p].erase(v);
                vis[v]=0;
                par[v]=0;
                v=p;
            }
            printf("%d\n", v);
            if(vec[v].size()!=0) dfs(v);
            return;
        }
        par[to]=v;
        dfs(to);
        return;
    }
    return;
}

int main()
{
    scanf("%d%d", &n, &m);
    vec.resize(n+1);
    par.resize(n+1);
    vis.resize(n+1);
    for(int i=1; i<=m; i++)
    {
        scanf("%d%d", &u, &v);
        if(vec[v].find(u)!=vec[v].end())
        {
            printf("%d %d\n", u, v);
            vec[u].erase(v);
            vec[v].erase(u);
        }
        else
        {
            vec[u].insert(v);
            vec[v].insert(u);
        }
    }
    for(int i=1; i<=n; i++)
    {
        if(vec[i].size()!=0)
        {
            dfs(i);
        }
    }
    return 0;
}

Compilation message (stderr)

postmen.cpp: In function 'int main()':
postmen.cpp:48:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |     scanf("%d%d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~
postmen.cpp:54:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   54 |         scanf("%d%d", &u, &v);
      |         ~~~~~^~~~~~~~~~~~~~~~

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