405235: GYM101853 J Smallest Difference

You are given an array a consists of n elements, find the maximum number of elements you can select from the array such that the absolute difference between any two of the chosen elements is  ≤ 1.

The first line contains an integer T (1 ≤ T ≤ 100), in which T is the number of test cases.

The first line of each test case consist of an integer n (2 ≤ n ≤ 10⁴), in which n is size of the array a

The a line follow containing n elements a₁, a₂, ..., a_n (1 ≤ a_i ≤ 10⁴), giving the array a.

For each test case, print a single line containing the maximum number of elements you can select from the array such that the absolute difference between any two of the chosen elements is  ≤ 1.

2
3
1 2 3
5
2 2 3 4 5

2
3