LeetCode 3131: Find the Integer Added to Array I

Meta Data

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Difficulty: easy First Attempt: 2024-04-28

• Submissions: Runtime Error → Wrong Answer → Accepted

Approach

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Adding the same x to every element of nums1 gives nums2 (possibly reordered), so the minimums also differ by x: x = min(nums2) - min(nums1). The difference of sums divided by the length also works, with integer division.

My Attempts

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Attempt 1 had a wrong variable name (NameError); attempt 2 divided the sum difference by the length with /, returning the float 5.0, judged wrong. Wrapping it in int passed.

Solution

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class Solution:
    def addedInteger(self, nums1: List[int], nums2: List[int]) -> int:
        return min(nums2) - min(nums1)

Complexity

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Time O(n), space O(1).

Mistakes to Avoid

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• / produces a float; the answer must be an integer.

Interview Explanation

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Since every element gains the same x, the two minimums differ by exactly x, so I return their difference. Time O(n).