Circular Sentence

Problem Description

A sentence is a list of words that are separated by a single space with no leading or trailing spaces. A sentence is circular if the last character of each word in the sentence is equal to the first character of its next word, and the last character of the last word is equal to the first character of the first word. Given a string sentence, return true if it is circular. Otherwise, return false.

Key Insights

• Each word in the sentence must connect to the next word via their last and first characters.
• The last word must connect back to the first word.
• The problem can be simplified by splitting the sentence into words and checking the necessary character connections.

Space and Time Complexity

Time Complexity: O(n), where n is the number of characters in the sentence. Each character is processed at most a couple of times. Space Complexity: O(m), where m is the number of words in the sentence, as we store the words in a list.

Solution

To determine if a sentence is circular, we can follow these steps:

1. Split the sentence into words based on spaces.
2. Check the last character of each word against the first character of the next word in a loop.
3. After checking the last word with the first word, if all checks pass, return true; otherwise, return false. We will use a list to store the words and perform character comparisons to validate the circular condition.

Code Solutions