class Solution:
    def averageOfLevels(self, root: Optional[TreeNode]) -> List[float]:

        def helper(qu):
            if not qu:
                return

            i = len(qu)
            leng = len(qu)
            total = 0

            while i > 0:
                poped = qu.popleft()
                total += poped.val

                if poped.left:
                    qu.append(poped.left)
                if poped.right:
                    qu.append(poped.right)            

                i -= 1
            ans.append(total/leng)
            helper(qu)
        qu = deque()
        qu.append(root)
        ans = []

        helper(qu)

        return ans

class Solution:
    def countOperations(self, num1: int, num2: int) -> int:
        count = 0
        while num1 and num2:
            if num1>=num2:
                count +=  num1//num2
                num1 =  num1%num2
            else:
                count +=  num2//num1
                num2 =  num2%num1
        return count

#include <bits/stdc++.h>
using namespace std;
class Solution {
    public :
        int solve (string s,int k){
            vector <int> freq(26);
            
            int l=0;int r=0;
            int offset=(int)'a';
            int ans=0;
            while (r<s.size()){
                if (r-l<k-1){   
                   freq[s[r]-offset]++;
                    r++;             
                }else if (r-l==k-1){
                    freq[s[r]-offset]++;
                    r++;
                    bool t=true;
                    for (int x:freq){
                        if (x>1){
                          t=false;
                        }
                    }
                    t?ans+=1:ans=ans;
                    
                }else if (r-l>k-1){
                    freq[s[l]-offset]--;
                    l++;
                }
                
            }
            return ans;
        }
};

int main () {
    string s="abcdefhijklmnopqrstuvwxyz";
    int k=5;
    Solution* sol=new Solution();
    cout<<sol->solve(s,k);
}