Applications (autocomplete, spell check, IP routing) in Data Structures Theory - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

How does autocomplete typically predict the next word?

Autocomplete systems often suggest the next word based on previous input. Which method best describes how they predict the next word?

A By using frequency of word sequences learned from large text data

B By randomly selecting words from a dictionary

C By checking spelling errors only

D By matching words only by their length

💡 Hint

Think about how your phone suggests words based on what you typed before.

Autocomplete uses patterns of word sequences and their frequencies learned from large text data to predict likely next words.

📋 Factual

intermediate

What data structure is commonly used in spell checkers to store dictionary words?

Spell checkers need to quickly find if a word exists in a dictionary. Which data structure is most commonly used for this purpose?

A Trie (prefix tree)

B Stack

C Queue

D Linked list

💡 Hint

It is a tree structure that stores words by their prefixes.

Tries store words by their prefixes, allowing fast lookup and prefix matching, which is ideal for spell checking.

🔍 Analysis

advanced

Why is IP routing often implemented using prefix matching?

IP routing tables use prefix matching to decide where to send packets. Why is prefix matching important in IP routing?

A Because IP addresses are random numbers with no structure

B Because prefix matching ignores the network part of the address

C Because prefix matching is slower but more secure

D Because IP addresses are hierarchical and prefixes represent network segments

💡 Hint

Think about how IP addresses group devices in networks.

IP addresses are hierarchical; prefixes represent network segments. Prefix matching helps routers efficiently find the best route for a packet.

❓ Comparison

advanced

Compare the use of tries in autocomplete and spell check applications.

Both autocomplete and spell check use tries. What is a key difference in how tries are used in these two applications?

A Spell check uses tries for storing user data; autocomplete does not use tries

B Autocomplete uses tries only for exact matches; spell check uses them for prefix matches

C Autocomplete uses tries to suggest completions; spell check uses tries to verify word existence and suggest corrections

D Both use tries only to store numbers, not words

💡 Hint

Think about what each application needs to do with the words.

Autocomplete uses tries to suggest possible word completions based on prefixes, while spell check uses tries to verify if a word exists and to find close matches for corrections.

❓ Reasoning

expert

What is the main challenge in implementing IP routing with very large routing tables?

As the internet grows, routing tables become very large. What is the main challenge routers face with large routing tables?

A Routers run out of memory to store all IP addresses individually

B Routers must find the longest prefix match quickly among many entries to forward packets efficiently

C Routers cannot perform prefix matching on large tables

D Routers only forward packets randomly when tables are large

💡 Hint

Consider what routers must do for each packet they receive.

Routers must quickly find the longest prefix match in large routing tables to decide the best path for each packet, which is computationally challenging as tables grow.