find-anagram-mappings.js

/**
 * Find Anagram Mappings
 *
 * Given two lists A and B, and B is an anagram of A.
 * B is an anagram of A means B is made by randomizing the order of the elements in A.
 *
 * We want to find an index mapping P, from A to B. A mapping P[i] = j means the ith element in A appears in B at index j.
 *
 * These lists A and B may contain duplicates. If there are multiple answers, output any of them.
 *
 * For example, given
 *
 * A = [12, 28, 46, 32, 50]
 * B = [50, 12, 32, 46, 28]
 * We should return
 * [1, 4, 3, 2, 0]
 * as P[0] = 1 because the 0th element of A appears at B[1], and P[1] = 4 because the 1st element of A appears at B[4], and so on.
 * Note:
 *
 * A, B have equal lengths in range [1, 100].
 * A[i], B[i] are integers in range [0, 10^5].
 */

/**
 * @param {number[]} A
 * @param {number[]} B
 * @return {number[]}
 */
const anagramMappings = (A, B) => {
  const map = {};

  B.forEach((number, index) => (map[number] = index));

  return A.map(number => map[number]);
};

export { anagramMappings };