Find Two Sum Indices

Given an array \(A\) of \(n\) integers and an integer \(target\), find two distinct indices \(i\) and \(j\) such that \(A[i] + A[j] = target\). The output should be the indices in ascending order formatted as a Python list. If no such pair exists, output an empty list.

You are required to implement a solution that efficiently finds the pair using a hash map (i.e. in approximately \(O(n)\) time complexity). If multiple answers exist, returning any valid one is acceptable.

inputFormat

The input is given via stdin and consists of:

1. An integer \(n\) representing the number of elements in the array.
2. \(n\) space-separated integers representing the array \(A\).
3. An integer \(target\) representing the target sum.

For example: 5\n2 7 11 15 -2\n9\n

outputFormat

Output the result to stdout as a Python list representation. If a valid pair is found, output the sorted indices enclosed in square brackets, for example: [0, 1]. If no such pair exists, output [].

5
2 7 11 15 -2
9

[0, 1]