Maximum Distance Pair of Equal Elements

Given an array of n integers, your task is to find two indices \( i \) and \( j \) (with \( i < j \)) such that the elements at these indices are equal (i.e., \( arr[i] = arr[j] \)) and the difference \( j - i \) is maximized. If there are multiple pairs with the same maximum difference, choose the pair with the smallest \( i \). If no such pair exists, output -1.

Note: The indices in the output should be 1-indexed.

Example:

• For n = 6 and arr = [1, 3, 1, 4, 5, 1], the answer is 1 6 because the first and last occurrence of 1 yield the maximum distance of 5.
• For n = 4 and arr = [1, 2, 3, 4], there are no equal elements, so the answer is -1.

inputFormat

The first line of input contains a single integer \( T \) representing the number of test cases. For each test case, the first line contains an integer \( n \) denoting the size of the array. The second line contains \( n \) space-separated integers which represent the array elements.

outputFormat

For each test case, output the answer in a separate line. If a valid pair is found, print two space-separated integers representing the 1-indexed positions \( i \) and \( j \). Otherwise, print -1.

## sample

2
6
1 3 1 4 5 1
5
7 7 7 7 7

1 6
1 5

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