Underscorify_Substring.md

Underscorify Substring

Problem Statement

Write a function that takes in two strings: a main string and a potential substring of the main string. The function should return a version of the main string with every instance of the substring in it wrapped between underscores. If two instances of the substring in the main string overlap each other or sit side by side, the underscores relevant to these two substrings should only appear on the far left of the left substring and on the far right of the right substring. If the main string does not contain the other string at all, return the main string intact.

Sample input:"testthis is a testtest to see if testestest it works","test"

Sample output:"_test_this is a _testtest_to see if_testestest_it works"

Explanation

We can use a Stack here

Solution

Check this Python code.