GFG Sum of Beauty of All Substrings

class Solution {
  public:
    int beautySum(string s) {
      int n=s.size();int ans=0;
        for(int l=2;l<=n;l++)
        {
            int i=0;
            int j=0;
            vector<int> freq(26,0);
            while(j<n)
            {
                freq[s[j]-'a']++;
                if((j-i+1)==l)
                {
                    //cout<<i<<" to "<<j<<" ";
                    //cout<<max_element(freq)-min_element(freq)<<endl;
                    ans=ans+(max_element(freq)-min_element(freq));
                    freq[s[i]-'a']--;
                    ++i;
                }
               
                ++j;
            }
        }
        //cout<<"Answer"<<endl;
        return ans;
    }
    int max_element(vector<int> &freq)
    {
        int maxi=0;
        for(int i=0;i<26;i++)
        {
            if(freq[i]!=0)
            {
                maxi=max(maxi,freq[i]);
            }
        }
        return maxi;
    }
     int min_element(vector<int> &freq)
    {
        int mini=INT_MAX;
        for(int i=0;i<26;i++)
        {
            if(freq[i]!=0)
            {
                mini=min(mini,freq[i]);
            }
        }
        return mini;
    }
};