Find the Prefix Common Array of Two Arrays
You are given two 0-indexed integer permutations A and B of length n.
A prefix common array of A and B is an array C such that C[i] is equal to the count of numbers that are present at or before index i in both A and B.
Return the prefix common array of A and B.
A sequence of n integers is called a permutation if it contains all integers from 1 to n exactly once.
Example 1
Input
A = [1,3,2,4], B = [3,1,2,4]Output
[0,2,3,4]At i = 0, no number is common; at i = 1, 1 and 3 are common; at i = 2, 1, 2, and 3 are common; at i = 3, 1, 2, 3, and 4 are common.
Example 2
Input
A = [2,3,1], B = [3,1,2]Output
[0,1,3]At i = 0, no number is common; at i = 1, only 3 is common; at i = 2, 1, 2, and 3 are common.
Constraints
- 1 <= A.length == B.length == n <= 50
- 1 <= A[i], B[i] <= n
- It is guaranteed that A and B are both a permutation of n integers.