3042.js

/** ------------------------------------------------------------------------------
 * 
 * 3042. Count Prefix and Suffix Pairs I
 * Topics: Array, String
 * https://leetcode.com/problems/count-prefix-and-suffix-pairs-i/?envType=daily-question&envId=2025-01-08
 * 
 ------------------------------------------------------------------------------ */
const isPrefixAndSuffix = (str1, str2) => {
  return str2.startsWith(str1) && str2.endsWith(str1)
}

/**
 * @param {string[]} words
 * @return {number}
 */
var countPrefixSuffixPairs = function (words) {
  let answer = 0

  for (let i = 0; i < words.length - 1; i++) {
    for (let j = i + 1; j < words.length; j++) {
      if (isPrefixAndSuffix(words[i], words[j])) {
        answer++
      }
    }
  }

  return answer
}

console.log(countPrefixSuffixPairs(["a", "aba", "ababa", "aa"]))