Contains duplicate#

Levels: level-0

Data structures: array, hash-table

Practice Link#

Description#

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.

Example#

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

Python Solution#

 1class Solution(object):
 2    def containsDuplicate(self, nums):
 3        """
 4        :type nums: List[int]
 5        :rtype: bool
 6        """
 7        h = {}
 8        for n in nums:
 9            if n in h:
10                return True
11            h[n] = True
12        return False
13
14
15class Solution2(object):
16    def containsDuplicate(self, nums):
17        """
18        :type nums: List[int]
19        :rtype: bool
20        """
21        return True if len(set(nums)) < len(nums) else False
22
23
24in_arrs = [
25    [2, 1, 2, 1, 0, 1, 2],
26    [3, 3, 5, 0, 0, 3, 1, 4],
27    [3, 5, 0, 1, 4],
28    [1, 2, 3, 1],
29    [1, 2, 3, 4],
30    [1, 1, 1, 3, 3, 4, 3, 2, 4, 2],
31]
32if __name__ == "__main__":
33
34    sol = Solution2()
35    for nin in in_arrs:
36        r = sol.containsDuplicate(nin)
37        print(r)