217.Contains_Duplicate_(Easy).md

217. Contains Duplicate (Easy)

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

Similar question on neetcode: https://neetcode.io/problems/duplicate-integer/

Question:

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.

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

KeyPoints:

This question is defintely faster to use set() to check for duplicate, and use the len to compare.

My Solution:

class Solution(object):
    def containsDuplicate(self, nums):
        """
        :type nums: List[int]
        :rtype: bool
        """
        return (len(nums) != len(set(nums)))

Slower Solution:

This method will timeout for large list

class Solution(object):
    def containsDuplicate(self, nums):
        """
        :type nums: List[int]
        :rtype: bool
        """
        n = 0
        for i in nums:
            if i in nums[n+1:]:
                return True
            n += 1
        return False