Score : $300$ points
Given are three sequences of length $N$ each: $A = (A_1, A_2, \dots, A_N)$, $B = (B_1, B_2, \dots, B_N)$, and $C = (C_1, C_2, \dots, C_N)$, consisting of integers between $1$ and $N$ (inclusive).
How many pairs $(i, j)$ of integers between $1$ and $N$ (inclusive) satisfy $A_i = B_{C_j}$?
Input is given from Standard Input in the following format:
$N$ $A_1$ $A_2$ $\ldots$ $A_N$ $B_1$ $B_2$ $\ldots$ $B_N$ $C_1$ $C_2$ $\ldots$ $C_N$
Print the number of pairs $(i, j)$ such that $A_i = B_{C_j}$.
3 1 2 2 3 1 2 2 3 2
4
Four pairs satisfy the condition: $(1, 1), (1, 3), (2, 2), (3, 2)$.
4 1 1 1 1 1 1 1 1 1 2 3 4
16
All the pairs satisfy the condition.
3 2 3 3 1 3 3 1 1 1
0
No pair satisfies the condition.