LeetCode之Contains Duplicate

/*Hash Table*/class Solution {public:    bool containsDuplicate(vector<int>& nums) {        unordered_map<int, int> count;        for(int i = 0; i < nums.size(); ++i){            if(count.find(nums[i]) != count.end()) ++count[nums[i]];            else count[nums[i]] = 1;        }        for(unordered_map<int, int>::iterator it = count.begin(); it != count.end(); ++it){            if(it->second > 1) return true;        }        return false;    }};