leetcode-217-contains duplicate

Given an array of integers, find if the array contains any duplicates. Your function should return true if any value appears at least twice in the array, and it should return false if every element is distinct.

给定一个数组，找出其是否包含重复元素。

简单的利用一个哈希表存储所有未重复数字，当发现重复数字即可返回true,否则返回false

class Solution {
    public:
        bool containsDuplicate(vector<int>& nums) {
            set<int> s;
            for(int i=0;i<nums.size();i++){
                if(s.find(nums[i])!=s.end()) return true;
                else s.insert(nums[i]);
            }
            return false;
        }
};