3042-count-prefix-and-suffix-pairs-i.js

/**
 * 3042. Count Prefix and Suffix Pairs I
 * https://leetcode.com/problems/count-prefix-and-suffix-pairs-i/
 * Difficulty: Easy
 *
 * You are given a 0-indexed string array words.
 *
 * Let's define a boolean function isPrefixAndSuffix that takes two strings, str1 and str2:
 * - isPrefixAndSuffix(str1, str2) returns true if str1 is both a prefix and a suffix of
 *   str2, and false otherwise.
 *
 * For example, isPrefixAndSuffix("aba", "ababa") is true because "aba" is a prefix of
 * "ababa" and also a suffix, but isPrefixAndSuffix("abc", "abcd") is false.
 *
 * Return an integer denoting the number of index pairs (i, j) such that i < j, and
 * isPrefixAndSuffix(words[i], words[j]) is true.
 */

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

  for (let i = 0; i < words.length; i++) {
    for (let j = i + 1; j < words.length; j++) {
      if (words[j].startsWith(words[i]) && words[j].endsWith(words[i])) {
        count++;
      }
    }
  }

  return count;
};