3043 - Find the Length of the Longest Common Prefix.

Medium

You are given two arrays with positive integers arr1 and arr2.

A prefix of a positive integer is an integer formed by one or more of its digits, starting from its leftmost digit. For example, 123 is a prefix of the integer 12345, while 234 is not.

A common prefix of two integers a and b is an integer c, such that c is a prefix of both a and b. For example, 5655359 and 56554 have a common prefix 565 while 1223 and 43456 do not have a common prefix.

You need to find the length of the longest common prefix between all pairs of integers (x, y) such that x belongs to arr1 and y belongs to arr2.

Return the length of the longest common prefix among all pairs. If no common prefix exists among them, return 0.

Example 1:

Input: arr1 = 1,10,100, arr2 = 1000

Output: 3

Explanation: There are 3 pairs (arr1i, arr2j):

• The longest common prefix of (1, 1000) is 1.

• The longest common prefix of (10, 1000) is 10.

• The longest common prefix of (100, 1000) is 100.

The longest common prefix is 100 with a length of 3.

Example 2:

Input: arr1 = 1,2,3, arr2 = 4,4,4

Output: 0

Explanation: There exists no common prefix for any pair (arr1i, arr2j), hence we return 0.

Note that common prefixes between elements of the same array do not count.

Constraints:

• <code>1 <= arr1.length, arr2.length <= 5 * 10⁴</code>

• <code>1 <= arr1i, arr2i<= 10⁸</code>