Solve island connectivity and string multiplication

Question

Given N distinct islands (e.g., a, b, c…) and a list of existing undirected paths between them, compute the minimum number of additional paths required so that all islands become connected. LeetCode 43. Multiply Strings – Given two non-negative integers represented as strings, return their product as a string. (Clarify whether the carry can exceed 10.)

https://leetcode.com/problems/multiply-strings/description/open_in_new