FindAnagramMappings760.java

/**
 * Given two lists Aand 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].
 */

public class FindAnagramMappings760 {
    /**
     * https://leetcode.com/problems/find-anagram-mappings/solution/
     */
    public int[] anagramMappings(int[] A, int[] B) {
        Map<Integer, Integer> D = new HashMap();
        for (int i = 0; i < B.length; ++i)
            D.put(B[i], i);

        int[] ans = new int[A.length];
        int t = 0;
        for (int x: A)
            ans[t++] = D.get(x);
        return ans;
    }

}