21North Interview Questions and Answers

To understand the supply of restaurants in a particular area of a city, we can use various methods.

• Collect data from online directories like Yelp, Zomato, etc.

• Conduct surveys to gather information about the number of restaurants in the area.

• Analyze the population density and demographics of the area to estimate the demand for restaurants.

• Check the number of restaurant permits issued by the local government.

• Use GIS mapp...read more

Diameter of a binary tree is the longest path between any two leaf nodes.

• Calculate the height of left and right subtrees recursively.

• Calculate the diameter recursively using the formula max(left_height + right_height + 1, max(left_diameter, right_diameter)).

• Return the maximum diameter.

To find interchanged terms from an AP series

• Identify the common difference between terms

• Swap the positions of adjacent terms

• Check if the new series is also an AP

• Repeat until no more interchanged terms can be found

Database indexing is a technique to improve the performance of database queries.

• Indexing creates a data structure that allows for faster retrieval of data.

• Indexes are created on one or more columns of a table.

• Queries that use indexed columns can be executed faster.

• Indexes can be clustered or non-clustered.

• Clustered indexes determine the physical order of data in a table.

• Non-clustered indexes create a separate structure...read more

DHCP is a protocol that assigns IP addresses to devices on a network. DNS is a system that translates domain names to IP addresses.

• DHCP assigns IP addresses to devices on a network

• DNS translates domain names to IP addresses

• DHCP reduces the need for manual IP address configuration

• DNS allows users to access websites using domain names instead of IP addresses