Given an array and a target integer, write a function
sum_pair_indices that returns the indices of two integers in the array that add up to the target integer. If not found, just return an empty list.
Note: Can you do it on time?
Note: Even though there could be many solutions, only one needs to be returned.
array = [1 2 3 4] target = 5
def sum_pair_indices(array, target) -> [0 3] or [1 2]
array =  target = 6
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Do NOT return [0 0] as you can't use an index twice.