#146EasyLists & Tuples· Traversal

Second Largest Value

Write `second_largest(numbers)` that returns the second largest **distinct** value in the list, or `None` if there is no such value (an empty list, one element, or all elements equal). Try to do it in a single pass without sorting.

Input format

`numbers`: a list of integers.

Output format

An integer, or `null` when there is no second largest distinct value.

Examples

Input: numbers = [4,9,2,9,7]

Output: 7

9 is the largest; the duplicate 9 does not count again, so the answer is 7.

Input: numbers = [5,5,5]

Output: null

There is only one distinct value.

Constraints

0 <= len(numbers) <= 10^5
-10^9 <= value <= 10^9

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Lists and Tuples in Python

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