Maximum Distance in Arrays — LeetCode 624 Python Solution

The problem

You are given m arrays, where each array is sorted in ascending order. You can pick up two integers from two different arrays (each array picks one) and calculate the distance.

Example

Input

arrays = [[1,2,3],[4,5],[1,2,3]]

Output

4

Explanation

One way to reach the maximum distance 4 is to pick 1 in the first or third array and pick 5 in the second array.

Python solution

class Solution:
    def maxDistance(self, arrays: List[List[int]]) -> int:
        ans = 0
        mi, mx = arrays[0][0], arrays[0][-1]
        for arr in arrays[1:]:
            a, b = abs(arr[0] - mx), abs(arr[-1] - mi)
            ans = max(ans, a, b)
            mi = min(mi, arr[0])
            mx = max(mx, arr[-1])
        return ans

Complexity

Pattern: Greedy

Take the locally best option every time — when you can prove that never costs you later. LeetCode 624. Maximum Distance in Arrays is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Greedy.

The greedy guide has the Python template for the pattern and the 346 LeetCode problems that use it.

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