#1207. Unique Number of Occurrences.cpp

class Solution {
    public:
        bool uniqueOccurrences(vector<int>& arr) {
            unordered_map<int,int> mp;
            unordered_set<int> st;
            for(int i=0;i<arr.size();i++)
            mp[arr[i]]++;
            for(auto ele:mp)
            st.insert(ele.second);
            return mp.size()==st.size();
        }
    };