The first round was a phone interview with questions related to Java, such as:

1. Explain exceptions and their types.
2. Explain final instance, final method, and final class.
3. Explain default access.
4. Explain nested classes, mainly static classes.

1. Implement a method to get the mirror of a binary tree.

2. Shuffle an array with equal distribution for selecting each index.

3. Print the level order of a binary tree in a zigzag manner.

4. Implement a digital watch.