CF1830B The BOSS Can Count Pairs

You are given two arrays $ a $ and $ b $ , both of length $ n $ . Your task is to count the number of pairs of integers $ (i,j) $ such that $ 1 \leq i < j \leq n $ and $ a_i \cdot a_j = b_i+b_j $ .

Each test contains multiple test cases. The first line of input contains a single integer $ t $ ( $ 1 \le t \le 10^4 $ ) — the number of test cases. The description of test cases follows. The first line of each test case contains a single integer $ n $ ( $ 2 \le n \le 2 \cdot 10^5 $ ) — the length of the arrays. The second line of each test case contains $ n $ integers $ a_1,a_2,\ldots,a_n $ ( $ 1 \le a_i \le n $ ) — the elements of array $ a $ . The third line of each test case contains $ n $ integers $ b_1,b_2,\ldots,b_n $ ( $ 1 \le b_i \le n $ ) — the elements of array $ b $ . It is guaranteed that the sum of $ n $ across all test cases does not exceed $ 2 \cdot 10^5 $ .

For each test case, output the number of good pairs.

In the first sample, there are $ 2 $ good pairs: - $ (1,2) $ , - $ (1,3) $ . In the second sample, there are $ 7 $ good pairs: - $ (1,2) $ , - $ (1,5) $ , - $ (2,8) $ , - $ (3,4) $ , - $ (4,7) $ , - $ (5,6) $ , - $ (5,7) $ .