Submission #13084981

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Source Code Expand

#include <bits/stdc++.h>
#define ll long long int
#define ld long double
#define ull unsigned long long int
#define forn(i,n)for(ll i=0;i<(n);i++)
#define forn_rev(i,n)for(ll i=(n)-1;i>=0;i--)
#define for1n(i,n) for(ll i=1;i<=(n);i++)
#define ARRAY_SIZE(a) sizeof(a)/sizeof(*a)
#define MOD 1000000007
#define MAXN 1000005

using namespace std;

vector<ll> adj[MAXN],parent(MAXN,-1),d(MAXN,0);
bool visited[MAXN];
ll dfs(){
    stack<ll> st;
    visited[0]=1;
    st.push(0);
    d[0]=1;
    while(!st.empty()){
        ll u=st.top();
        st.pop();
        forn(v,adj[u].size()){
            if(!visited[adj[u][v]]){
                visited[adj[u][v]]=1;
                st.push(adj[u][v]);
                d[adj[u][v]]=d[u]+1;
            }
            else {
                return adj[u][v];
            }

        }


    }
    return 0;

}


int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(NULL); cout.tie(NULL);
    memset(visited,0,sizeof visited);
    ll T=1;
    //cin>>T;
    while(T--)
    {
        ll N,K;
        cin>>N>>K;
        forn(i,N){
            ll u;
            cin>>u;
            adj[i].push_back(u-1);
        }
        ll start=dfs();
        ll cycle=1,cur=start;
        while(1){
            cur=adj[cur][0];
            if(cur==start && cycle>0){
                break;
            }
            else{
                cycle++;
            }
        }
        K-=d[start]-d[0];
        //cout<<cycle<<start<<endl;
        K%=cycle;
        cur=start;
        forn(i,K){
            cur=adj[cur][0];
        }
        cout<<cur+1;



    }



    return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘long long int dfs()’:
./Main.cpp:5:30: warning: comparison of integer expressions of different signedness: ‘long long int’ and ‘std::vector<long long int>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
    5 | #define forn(i,n)for(ll i=0;i<(n);i++)
      |                              ^
./Main.cpp:24:9: note: in expansion of macro ‘forn’
   24 |         forn(v,adj[u].size()){
      |         ^~~~

Judge Result