Description
https://leetcode.com/problems/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.
Example 1:
Input: [1,2,3,1] Output: true
Example 2:
Input: [1,2,3,4] Output: false
Example 3:
Input: [1,1,1,3,3,4,3,2,4,2] Output: true
Explanation
Simply use a hashmap to check if getting duplicates.
Python Solution
class Solution:
def containsDuplicate(self, nums: List[int]) -> bool:
counter = set()
for num in nums:
if num not in counter:
counter.add(num)
else:
return True
return False- Time complexity : O(N).
- Space complexity : O(N).