Google Interview Experience for Internship (Coding Round)

Google Internship (North America) coding round was held between 28th August to 5th September 2020 by Google(NA) for Software Engineering students of Pre-final and final year. The level of this Coding Round was easy.  The coding round comprised of two questions which are as follows :

Question 1: Most Booked Hotel Room

Problem Description: Given a hotel which has 10 floors [0-9] and each floor has 26 rooms [A-Z]. You are given a sequence of rooms, where + suggests the room is booked, – the room is freed. You have to find the number of rooms that were booked.

You may assume that the list describes a correct sequence of bookings in chronological order; that is, only free rooms can be booked, and only booked rooms can be freed. 

You may assume:

• N (length of input) is an integer within the range [1, 600]
• Each element of array A is a string consisting of three characters: “+” or “-“; a digit “0”-“9”; and uppercase English letter “A” – “Z”

Example:

Input: ["+1A", "+3E", "-1A", "+4F", "+1A", "-3E"]
Output: 4
Explanation: 4 rooms are booked at this time.
Input: ["-1C", "-3F", "-1L", "-ZF", "-1R", "-3E"]
Output: 0
Explanation: All rooms are free.

Question 2: Maximum Time

Problem Description: You are given a string that represents time in the format HH: MM. Some digits are blank (represented by ?). Fill in? With the same digit such that the time represented by this string is the maximum possible.

 Maximum time: 23:59, minimum time: 00:00. You can assume that the input string is always valid.

Example :

Input: "?4:5?"
Output: "14:51"
Input: "23:5?"
Output: "23:59"
Input: "0?:??"
Output: "05:55"
Input: "??:??"
Output: "22:22"