1455 - Check If a Word Occurs As a Prefix of Any Word in a Sentence

Given a sentence that consists of some words separated by a single space, and a searchWord, check if searchWord is a prefix of any word in sentence.

Return the index of the word in sentence (1-indexed) where searchWord is a prefix of this word. If searchWord is a prefix of more than one word, return the index of the first word (minimum index). If there is no such word return -1.

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

 Example 1:

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

Example 2:

Input: sentence = "this problem is an easy problem", searchWord = "pro"
Output: 2
Explanation: "pro" is prefix of "problem" which is the 2nd and the 6th word in the sentence, but we return 2 as it's the minimal index.

Example 3:

Input: sentence = "i am tired", searchWord = "you"
Output: -1
Explanation: "you" is not a prefix of any word in the sentence.

 Constraints:

• 1 <= sentence.length <= 100
• 1 <= searchWord.length <= 10
• sentence consists of lowercase English letters and spaces.
• searchWord consists of lowercase English letters.

C++

class Solution {
public:
    int isPrefixOfWord(string sentence, string searchWord) {
        stringstream ss(sentence);
        string s;
        for (int i = 1; ss >> s; ++i) {
            if (s.find(searchWord) == 0) {
                return i;
            }
        }
        return -1;
    }
}

JAVA

• class Solution {
      public int isPrefixOfWord(String sentence, String searchWord) {
          String[] words = sentence.split(" ");
          for (int i = 0; i < words.length; ++i) {
              if (words[i].startsWith(searchWord)) {
                  return i + 1;
              }
          }
          return -1;
      }
  }

PYTHON

class Solution:
    def isPrefixOfWord(self, sentence: str, searchWord: str) -> int:
        words = sentence.split()
        for i, word in enumerate(words, 1):
            if word.startswith(searchWord):
                return i
        return -1