Submission #718528

#	Time	Username	Problem	Language	Result	Execution time	Memory
718528		Augustyn	Naboj (COCI22_naboj)	C++17	110 / 110	267 ms	15180 KiB

naboj

#include<bits/stdc++.h>
using namespace std;
#define x 200001
int n,m,sw[x],odp[x],it;
vector<int>p[x];
bool jo[x],to[x];
bool dfs(int t)
{
    jo[t]=to[t]=1;
    for(int i:p[t])
    {
        if(to[i]==1)
            return 1;
        if(jo[i]==0)
            if(dfs(i))
                return 1;
    }
    to[t]=0;
    odp[++it]=t;
    return 0;
}
int main()
{
    scanf("%d%d",&n,&m);
    while(m)
    {
        --m;
        int a,b;
        scanf("%d%d",&a,&b);
        p[b].push_back(a);
        sw[a]++;
    }
    for(int i=1;i<=n;++i)
        if(sw[i]==0)
            if(dfs(i))
            {
                printf("-1");
                return 0;
            }
    if(it!=n)
    {
        printf("-1");
        return 0;
    }
    printf("%d\n",n);
    for(int i=1;i<=n;++i)
        printf("%d 0\n",odp[i]);
    return 0;
}

Compilation message (stderr)

naboj.cpp: In function 'int main()':
naboj.cpp:24:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   24 |     scanf("%d%d",&n,&m);
      |     ~~~~~^~~~~~~~~~~~~~
naboj.cpp:29:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 |         scanf("%d%d",&a,&b);
      |         ~~~~~^~~~~~~~~~~~~~

• Subtask 1: 15 / 15
• Subtask 2: 25 / 25
• Subtask 3: 70 / 70