760. Find Anagram Mappings
Tags: ‘Hash Table’
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, Bhave equal lengths in range[1, 100].A[i], B[i]are integers in range[0, 10^5].
Solution
public int[] anagramMappings(int[] A, int[] B) {
Map<Integer, Integer> map = new HashMap<>();
int[] result = new int[A.length];
for (int i = 0; i < B.length; i++) {
map.put(B[i], i);
}
int i = 0;
for (int a: A) {
result[i++] = map.get(a);
}
return result;
}