Shared code

/*

Set time here:
    Start: 2021-06-17 09:03:51
    End(when AC):

*/


/*
Author: Shobhit Tewari
*/

#define __STDC_LIMIT_MACROS
#include<iostream>
#include<vector>
#include<set>
#include<map>
#include<unordered_map>
#include<queue>
#include<stack>
#include<cstring>
#include<algorithm>
using namespace std;

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
template<class T> using oset =  tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

#define int long long
#define null 0
#define fio ios_base::sync_with_stdio(false); cin.tie(null);

#define pb push_back
#define sz(v) (int)(v.size())
#define all(v) v.begin(), v.end()

template<class T> using PQ = priority_queue<T>;
template<class T> using RPQ = priority_queue<T, vector<T>, greater<T>>;

const int mod = 1e9 +7;
const int infinity = INT64_MAX;
const double pi = 3.1415926535897932384626433832795;

void solve(){
    int n, k;
    cin >> n >> k;
    int arr[n];
    for(int i=0;i<n;i++) cin >> arr[i];
    int ans = 0;
    unordered_map<int, int> mp;
    int start = 0;
    int end = 0;
    int unique = 0;
    while(end < n) {
        mp[arr[end]]++;
        if(mp[arr[end]] == 1) unique++; 
        if(unique > k) {
            ans+=((end-start)*(end-start+1))/2;
            while(start <= end && unique > k) {
                mp[arr[start]]--;
                if(mp[arr[start]] == 0) { unique--; }
                start++;
            }
            ans-=((end-start)*(end-start+1))/2;
        }
        end++;
    }
    ans+=((end-start)*(end-start+1))/2;
    cout << ans << "\n";
}

signed main(){
    fio;
    int t=1;
    //cin >> t;
    while(t--){
        solve();
    }
    return 0;
}