First Repeating Element in Array | Dataford Interview Questions

Implement a function to find the first repeating element in an array.

Return the element whose first occurrence has the smallest index among all repeated values. Return -1 if every element is unique.

Input: a list of integers. Output: an integer.

Examples: [10, 5, 3, 4, 3, 5, 6] returns 5; [1, 2, 3, 4] returns -1.

Constraints: the array contains 1 to 1,000 integers, and values may be negative.

def first_repeating_element(nums):

Your question is First Repeating Element in Array. Start with the requirements in the Question tab.

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Implement a function to find the first repeating element in an array.

Return the element whose first occurrence has the smallest index among all repeated values. Return -1 if every element is unique.

Input: a list of integers. Output: an integer.

Examples: [10, 5, 3, 4, 3, 5, 6] returns 5; [1, 2, 3, 4] returns -1.

Constraints: the array contains 1 to 1,000 integers, and values may be negative.

def first_repeating_element(nums):

Your question is First Repeating Element in Array. 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.