|All-time Popular Problems|
|Find duplicates in an array|
|Triplet Sum in Array|
|Sorting Elements of an Array by Frequency|
|Search an Element in an array|
|Diameter of Binary Tree|
|Maximum of all subarrays of size k|
|Leaders in an array|
|Find median in a stream|
|Reverse a Linked List in groups of given size.|
In a given array A find the maximum value of (A[i] – i) - (A[j] – j) where i is not equal to j.
i and j vary from 0 to n-1 and N is size of input array A. Value of N is always greater than 1.
The first line of input contains a single integer T denoting the number of test cases. Then T test cases follow. Each test case consist of two lines. The first line of each test case consists of an integer N, where N is the size of array.The second line of each test case contains N space separated integers denoting array elements.
Corresponding to each test case, in a new line, print the maximum value.
1 ≤ T ≤ 100
2 ≤ N ≤ 200
1 ≤ A[i] ≤ 1000
9 15 4 12 13
(a-1) - (a-2) = (15-1)-(4-2) = 12