1207_UniqueNumberofOccurrences - a920604a/leetcode GitHub Wiki

class Solution {
public:
    bool uniqueOccurrences(vector<int>& arr) {
        unordered_map<int, int> mp;
        unordered_set<int> s;
        for(int a:arr) mp[a]++;
        for(auto it = mp.begin() ; it!=mp.end() ; ++it)
        {
            if(s.count(it->second)) return false;
            s.insert(it->second);
        }
        return true;
        
    }
};