Count Duplicates in List | Dataford Interview Questions

Write a function that counts the duplicates in a list.

Return the number of duplicate occurrences, counting every appearance after the first occurrence of a value. For example, [1, 2, 2, 3, 3, 3] contains three duplicate occurrences. Implement count_duplicates(nums), where nums is a list of hashable values and the result is an integer.

Constraints

0 <= len(nums) <= 100000
Every element in nums is hashable
Count duplicate occurrences, not distinct values that appear more than once

Function Signature

def count_duplicates(nums):

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Problem

Write a function that counts the duplicates in a list.

Constraints

0 <= len(nums) <= 100000
Every element in nums is hashable
Count duplicate occurrences, not distinct values that appear more than once

Function Signature

def count_duplicates(nums):

Your question is Count Duplicates in List. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.