Check If A Word Occurs As A Prefix Of Any Word In A Sentence - Leetcode Solution

Problem Statement:

Given a sentence and a string s, return true if s is a prefix of any word in the sentence.

A prefix of a string s is any leading contiguous substring of s.

Example:

Input: sentence = "i love eating burger", searchWord = "burg" Output: 4 Explanation: "burg" is prefix of "burger" which is the 4th word in the sentence.

Solution:

One way to solve this problem is to split the sentence into words and check if s is a prefix of any word. If a prefix is found, we return the index of the word in the sentence.

Here's the step by step guide to solve this problem in Python:

1. Split the sentence into words using the "split()" function:

sentence = sentence.split()

2. Use a for loop to iterate through each word in the sentence:

for i, word in enumerate(sentence):

3. Check if the word starts with the given searchWord:

if word.startswith(searchWord):

4. If the word starts with the searchWord, return the index of the word in the sentence:

return i+1 # index of the word in the sentence starts from 1

5. If no prefix is found, return -1 to indicate that the searchWord is not a prefix of any word in the sentence:

return -1

Here's the full Python code to solve this problem:

class Solution: def isPrefixOfWord(self, sentence: str, searchWord: str) -> int: sentence = sentence.split() for i, word in enumerate(sentence): if word.startswith(searchWord): return i+1 # index of the word in the sentence starts from 1 return -1

Time Complexity:

The time complexity of this solution is O(n*m), where n is the number of words in the sentence and m is the length of the searchWord. This is because we need to iterate through each word in the sentence and check if it starts with the searchWord.

Space Complexity:

The space complexity of this solution is O(n), where n is the number of words in the sentence. This is because we are storing the sentence as a list of words.

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