deeprun

Contains Duplicate 

 문제 설명

Given an integer array nums, return true if any value appears at least twice in the array, and return false if every element is distinct.

 제한 사항

• 1 <= nums.length <= 105
• -109 <= nums[i] <= 109

 입출력 예

Example 1:

Input: nums = [1,2,3,1]
Output: true

Example 2:

Input: nums = [1,2,3,4]
Output: false

Example 3:

Input: nums = [1,1,1,3,3,4,3,2,4,2]
Output: true

 Python 코드

Python code 

class Solution:
    def containsDuplicate(self, nums: List[int]) -> bool:
        return len(set(nums)) != len(nums)

* 참고 링크 : https://leetcode.com/problems/contains-duplicate/discuss/1159570/Python-99.25-faster

https://leetcode.com/problems/contains-duplicate/discuss/471215/Python-sol-by-native-set-and-length.-run-time-90%2B

class Solution:
    def containsDuplicate(self, nums: List[int]) -> bool:
    	hashset = set()
        
        for n in nums:
        	if n in hashset:
            	    return True
        	hashset.add()
        return False

* 참고 링크 : https://www.youtube.com/watch?v=3OamzN90kPg 

 C++ 코드

C ++ code

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

* 참고 링크 : https://kkminseok.github.io/posts/leetcode_Contains_Duplicate/

 출처

https://leetcode.com/problems/contains-duplicate/