Minimum Adjacent Weight Difference

You are given several test cases. In each test case, you are given an integer \(n\) and a list of \(n\) integers representing the weights of books. Your task is to compute the minimum possible difference between any two adjacent weights after sorting the list in non-decreasing order.

More formally, given a sorted list of weights \(w_1 \le w_2 \le \cdots \le w_n\), find

[ \min_{1 \le i < n} {w_{i+1} - w_i} ]

If a test case contains only one weight (i.e. (n = 1)), output inf (infinity) as there is no pair to compare.

Example:

• For \(n = 3\) with weights [3, 2, 1], after sorting the list becomes [1, 2, 3] and the minimum adjacent difference is \(2-1 = 1\).

inputFormat

The input begins with an integer \(T\) denoting the number of test cases. Each test case consists of:

1. An integer \(n\) representing the number of books.
2. A line with \(n\) space-separated integers representing the weights of the books.

Input is read from standard input (stdin).

outputFormat

For each test case, output a single line containing the minimum difference between any two adjacent weights after sorting. If there is only one weight in the test case, output inf. Output is written to standard output (stdout).

## sample

4
3
3 2 1
4
4 1 3 2
3
5 5 5
4
1 100 500 1000

1
1
0
99

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