I applied through Glassdoor and received a response pretty quickly. I was given a coding challenge with two questions:

• Convert a string to a long without using library functions in any programming language.
• Implement insert and delete operations in a ternary search tree.

A ternary search tree is similar to a binary search tree but has an additional node under the parent node for the same value. For example, a node with the value 5 might have 4 on its left and 6 on its right, and also have another 5 directly below it. Each node can have up to three children.

The recruiter emailed, stating, "Do it at your own time." As I had other interviews lined up for the week, I completed it within exactly one week. I got the answers right and checked every possible way and test case. However, the main reason for my decline, I believe, was the time taken to submit the coding challenge. It took me exactly one day to finish it, but I cannot explain this, so I was rejected.

Ternary search tree deletion.