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Easy · hash map

Given a list of integers nums, return True if any value appears at least twice in the list. Return False if every value is different.

You only need a yes or no answer. You do not have to say which value repeats or where it is. A list with a single number can never have a repeat, so the answer there is False.

Examples

Example 1

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

Output: True

The value 1 appears at index 0 and again at index 3.

Example 2

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

Output: False

Every number appears exactly once.

Example 3

Input: nums = [3, 3, 3, 3]

Output: True

Constraints