Submission #404256

#	TimeUTC-0	Username	Problem	Language	Result	Execution time	Memory
404256	2021-05-14 03:04:11	ftkbrian	Cactus? Not cactus? (kriii1_C)	C++14	0 / 1	2 ms	2636 KiB

C

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#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define pb push_back
///간단히 생각해보면 cactus는 전체에서 사이클이 하나여야 함을 알 수 있음
///tree에 역행간선 하나 존재시 cactus일 것
///dfsordering + 깊이 저장 후 역행 간선 개수 2개 이상인 정점 개수 찾기
ll n,m,dep[101010],chk;
vector<ll> V[101010];
void dfs(ll tar,ll p)
{
    if(dep[tar]) return;
    dep[tar] = dep[p]+1;
    for(auto i : V[tar])
        dfs(i,tar);
}
main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0),cout.tie(0);
    cin>>n>>m;
    for(int i = 0 ; i < m ; i++)
    {
        ll a,b; cin>>a>>b;
        V[a].pb(b), V[b].pb(a);
    }
    dfs(1,1);
    for(int i = 1 ; i <= n ; i++)
    {
 
 
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Compilation message (stderr)

C.cpp:17:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   17 | main()
      | ^~~~

• Subtask 1: 0 / 1