Unique Number of Occurrences

class Solution {
public:
    bool uniqueOccurrences(vector<int>& arr) {
       vector<int>ans;
        // sort the given array
        sort(arr.begin(),arr.end());
        
        // counting the occurence
        
        int count = 1;
        for(int i=0; i<arr.size();i++){
            if(i+1 < arr.size()){      // check element is in the arry
                if(arr[i]==arr[i+1]){
                    count++;
                }
                else{
                    ans.push_back(count);
                    count = 1;
                }
            }
            else{
                ans.push_back(count);
            }
        }
        // occurence are stored in ans vector , now sort the ans vector
        
        sort(ans.begin(),ans.end());
        
        //check the repetation of occurence 
        //if repetation is found --> return false
       //   else return true
        
        for(int i =0; i<ans.size();i++){
            if(i+1 < ans.size()){
                if(ans[i] == ans[i+1]){
                    return false;
                }
                
            }
        }
        return true;
    }
};