217. Contains Duplicate

class Solution {
public:
    bool containsDuplicate(vector<int>& nums) {
        unordered_map<int,int> h;
        bool flag=false;
        for(int i=0;i<nums.size();i++){
            h[nums[i]]++;
        }
        for(auto i:h){
            if(i.second>1){
                flag=true;
                break;
            }
        }
        return flag;
    }
};