Word Break Problem in DSA C - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the Word Break Problem?

It is a problem where we check if a given string can be split into a sequence of dictionary words.

beginner

What data structure is commonly used to store the dictionary in the Word Break Problem?

A hash set or trie is commonly used to quickly check if a substring exists in the dictionary.

intermediate

What is the main idea behind the dynamic programming solution to the Word Break Problem?

Use a boolean array where each position indicates if the substring up to that position can be segmented into dictionary words.

beginner

In the Word Break Problem, what does dp[i] = true represent?

It means the substring from the start up to index i can be segmented into dictionary words.

intermediate

Why do we check all substrings ending at position i in the Word Break Problem?

To find if any previous valid segmentation combined with a dictionary word ending at i forms a valid segmentation up to i.

What does the Word Break Problem ask you to determine?

A If a string contains only vowels

B If a string can be segmented into dictionary words

C If a string is a palindrome

D If a string contains digits

The problem is about checking if the string can be split into valid dictionary words.

Which data structure helps to quickly check if a substring is in the dictionary?

A Queue

B Stack

C Hash set

D Linked list

A hash set allows fast lookup to check if a substring exists in the dictionary.

In dynamic programming for Word Break, what does dp[0] usually represent?

A Empty string can be segmented

B First character is a dictionary word

C No segmentation possible

D Length of the string

dp[0] is true because an empty string is considered segmented.

If dp[j] is true and substring s[j:i] is in dictionary, what should dp[i] be?

A Same as dp[j]

B False

C Undefined

D True

This means substring up to i can be segmented, so dp[i] is true.

What is the time complexity of the dynamic programming solution for Word Break with string length n?

A O(n^2)

B O(n)

C O(n!)

D O(log n)

We check all substrings, leading to O(n^2) time complexity.

Explain how dynamic programming is used to solve the Word Break Problem.

Think about how you can use previous results to decide if the current substring can be segmented.

Describe the role of the dictionary and how it affects the Word Break Problem solution.

Consider how you decide if a substring is valid or not.