Light OJ 1129 / Trie Basic

/***
 created: 2023-02-23-00.15.00
***/

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template<typename U> using ordered_set=tree<U, null_type,less<U>,rb_tree_tag,tree_order_statistics_node_update>;
#define ll long long
#define all(we) we.begin(),we.end()
#define test int tt; cin>>tt; for(int cs=1;cs<=tt;cs++)
#define nl '\n'

ll ans=0;
ll tr[100005][11],v[100005],id=0;
void insert1(string &a)
{
    ll now=0;
    for(ll i=0;a[i];i++)
    {
        if(tr[now][(a[i]-'0')]==0)
        {
            tr[now][(a[i]-'0')]=++id;
        }
        else if(tr[now][(a[i]-'0')] && i==a.size()-1)
        {
            ans=0;
        }
        now=tr[now][(a[i]-'0')];
        if(v[now])
        {
            ans=0;
        }
    }
    v[now]=1;
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);


    test
    {
        ll n,m,i,j,k,l;
        cin>>n;
        string a;
        ans=1;
        id=0;
        memset(tr,0,sizeof tr);
        memset(v,0,sizeof v);

        for(i=0;i<n;i++)
        {
            cin>>a;
            insert1(a);
        }

        cout<<"Case "<<cs<<": ";
        if(ans) cout<<"YES"<<nl;
        else cout<<"NO"<<nl;
    }


    return 0;
}