# Solving Leetcode Interviews in Seconds with AI: Contains Duplicate


	# Introduction
	In this blog post, we will explore how to solve the LeetCode problem "217" using AI. LeetCode is a popular platform for preparing for coding interviews, and with the help of AI tools like [Chatmagic](https://www.chatmagic.app), we can generate solutions quickly and efficiently - helping you pass the interviews and get the job offer without having to study for months.

	# Problem Statement
	> 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 Explanation: The element 1 occurs at the indices 0 and 3.  Example 2:  Input: nums = [1,2,3,4] Output: false Explanation: All elements are distinct.  Example 3:  Input: nums = [1,1,1,3,3,4,3,2,4,2] Output: true    Constraints:  1 <= nums.length <= 105 -109 <= nums[i] <= 109  

	# Explanation
	*   **Hashing:** Utilize a hash set (or dictionary) to efficiently check for the presence of each number in the input array.
*   **Early Exit:** Immediately return `true` if a duplicate is found during the iteration. This avoids unnecessary processing.

*   **Runtime Complexity:** O(n), where n is the length of the input array.
*   **Storage Complexity:** O(n) in the worst case, where n is the number of distinct elements in the array (occurs if all elements are unique).

	
	# Code
	```python
	def containsDuplicate(nums: list[int]) -> bool:
    """
    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.
    """
    seen = set()
    for num in nums:
        if num in seen:
            return True
        seen.add(num)
    return False
	```