Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.
If you've seen these problems, a virtual contest is not for you - solve these problems in the archive.
If you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.
Never use someone else's code, read the tutorials or communicate with other person during a virtual contest.

No tag edit access

The problem statement has recently been changed. View the changes.

×
D. Same Differences

time limit per test

2 secondsmemory limit per test

256 megabytesinput

standard inputoutput

standard outputYou are given an array $$$a$$$ of $$$n$$$ integers. Count the number of pairs of indices $$$(i, j)$$$ such that $$$i < j$$$ and $$$a_j - a_i = j - i$$$.

Input

The first line contains one integer $$$t$$$ ($$$1 \le t \le 10^4$$$). Then $$$t$$$ test cases follow.

The first line of each test case contains one integer $$$n$$$ ($$$1 \le n \le 2 \cdot 10^5$$$).

The second line of each test case contains $$$n$$$ integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \le a_i \le n$$$) — array $$$a$$$.

It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.

Output

For each test case output the number of pairs of indices $$$(i, j)$$$ such that $$$i < j$$$ and $$$a_j - a_i = j - i$$$.

Example

Input

4 6 3 5 1 4 6 6 3 1 2 3 4 1 3 3 4 6 1 6 3 4 5 6

Output

1 3 3 10

Codeforces (c) Copyright 2010-2022 Mike Mirzayanov

The only programming contests Web 2.0 platform

Server time: May/22/2022 15:10:55 (g2).

Desktop version, switch to mobile version.

Supported by

User lists

Name |
---|