Find Pair with Sum

You are given an array of integers and a target integer \(T\). Your task is to determine whether there exist two distinct elements in the array whose sum is exactly \(T\). If such a pair exists, output the indices (0-indexed) of these two numbers in increasing order. Otherwise, output None.

Note: Each array will have at most one solution. The input is provided via standard input (stdin) and the result must be printed to standard output (stdout).

Input Format: The first line contains an integer \(n\) denoting the number of elements in the array. The second line contains \(n\) space-separated integers representing the array. The third line contains the target integer \(T\).

Output Format: If a valid pair is found, print two integers representing the indices of the two numbers separated by a space. Otherwise, print None.

inputFormat

The input is given in three lines from standard input (stdin):

• The first line contains an integer \(n\) indicating the number of elements in the array.
• The second line contains \(n\) space-separated integers representing the array.
• The third line contains a single integer \(T\) which is the target sum.

outputFormat

Output a single line:

• If a valid pair exists, output two space-separated integers \(i\) and \(j\) (with \(i < j\)) representing the indices of the two numbers whose sum equals \(T\).
• If no such pair exists, output None.

4
2 7 11 15
9

0 1