2025-04-15 13:14:06 +0000 UTC

from sortedcontainers import SortedList
from typing import List

class Solution:
    def goodTriplets(self, nums1: List[int], nums2: List[int]) -> int:

        index_map = {num: i for i, num in enumerate(nums2)}
  
        indices = [index_map[num] for num in nums1]

        left_counts = []
        left_sorted = SortedList()
        for idx in indices:
            left_counts.append(left_sorted.bisect_left(idx))
            left_sorted.add(idx)

        right_counts = []
        right_sorted = SortedList()
        for idx in reversed(indices):
            right_counts.append(len(right_sorted) - right_sorted.bisect_right(idx))
            right_sorted.add(idx)
        right_counts.reverse() 
        
        return sum(left * right for left, right in zip(left_counts, right_counts))