코테준비 - Contains Duplicate

Contains Duplicate

class Solution {
public:
  bool containsDuplicate(vector<int>& nums) {
      unordered_set<int> set;
      for(auto &num:nums){
          if (set.find(num) != set.end()) {
              return true;
          }
          set.insert(num);
      }
      return false;
  }
};