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].Intuition
Take the example A = [12, 28, 46], B = [46, 12, 28]. We want to know where the 12 occurs in B, say at position 1; then where the 28 occurs in B, which is position 2; then where the 46 occurs in B, which is position 0.
If we had a dictionary (hash table) D = {46: 0, 12: 1, 28: 2}, then this question could be handled easily.
Algorithm
Create the hash table D as described above. Then, the answer is a list of D[A[i]] for i = 0, 1, ....
Complexity Analysis
Time Complexity: , where is the length of .
Space Complexity: .
Analysis written by: @awice.