challenges-67.js

// #Question 2255. Count Prefixes of a Given String
// You are given a string array words and a string s, where words[i] and s comprise only of lowercase English letters.

// Return the number of strings in words that are a prefix of s.

// A prefix of a string is a substring that occurs at the beginning of the string. A substring is a contiguous sequence of characters within a string.

// Example 1:

// Input: words = ["a","b","c","ab","bc","abc"], s = "abc"
// Output: 3
// Explanation:
// The strings in words which are a prefix of s = "abc" are:
// "a", "ab", and "abc".
// Thus the number of strings in words which are a prefix of s is 3.
// Example 2:

// Input: words = ["a","a"], s = "aa"
// Output: 2
// Explanation:
// Both of the strings are a prefix of s.
// Note that the same string can occur multiple times in words, and it should be counted each time.

// #Solution

var countPrefixes = function (words, s) {
  let count = 0;

  for (let word of words) {
    if (s.startsWith(word)) {
      count++;
    }
  }

  return count;
};

countPrefixes(["a", "b", "c", "ab", "bc", "abc"], "abc");