leetcode217 存在重复元素

class Solution {
public:
    bool containsDuplicate(vector<int>& nums) 
    {
        map<int,int> good;
        int n = nums.size();
        for(int i = 0 ; i < n ; i++)
        {
            if(good.count(nums[i]) == 0)
            {
                good.insert(pair<int,int> (nums[i],1));
            }
        }
        return !(n == good.size());
    }
};

class Solution {
public:
    bool containsDuplicate(vector<int>& nums) 
    {
        sort(nums.begin(), nums.end());
        int n = nums.size();
        for (int i = 0; i < n - 1; i++) {
            if (nums[i] == nums[i + 1]) {
                return true;
            }
        }
        return false;
    }
};