A - Longest k-Good Segment

#include <bits/stdc++.h>
using namespace std;
#define maxn 1000006
int vis[maxn],b[maxn];
int n,k,ansl,ansr;
int main()
{
    cin>>n>>k;
    int j=0,num=0,maxx=0;
    for(int i=1; i<=n; i++)
    {
        cin>>b[i];
        if(!vis[b[i]])
        {
            vis[b[i]]++;
            num++;
            if(num>k)
            {
                for(j=j+1; j<i; j++)
                {
                    vis[b[j]]--;
                    if(vis[b[j]] == 0)
                    {
                        break;
                    }
                }
                num--;
            }
        }
        else
            vis[b[i]]++;
        if(i-j>maxx)
        {
            maxx =i-j;
            ansl=j;
            ansr=i;
        }
    }
    cout<<ansl+1<<" "<<ansr<<endl;
    return 0;
}