# https://leetcode.com/problems/find-the-prefix-common-array-of-two-arrays

from typing import List

class Solution:
    def findThePrefixCommonArray(self, A: List[int], B: List[int]) -> List[int]:
        result = []
        count = {}
        curr = 0
        for i in range(len(A)):
            count[A[i]] = count.get(A[i], 0) + 1
            if count[A[i]] > 1:
                curr += 1
            count[B[i]] = count.get(B[i], 0) + 1
            if count[B[i]] > 1:
                curr += 1
            result.append(curr)
        return result