Sum of N-Digit Palindromes

Determine the sum of all N-digit palindromes for a given integer 'N'. A palindrome is defined as a number that remains the same when its digits are reversed.

Example:

Input:

T = 1
N = 1

Output:

45

Explanation:

For N = 1, the numbers are [1, 2, 3, 4, 5, 6, 7, 8, 9, 0] and all are palindromes. Their sum is 45.

Constraints:

• 1 ≤ T ≤ 50
• 1 ≤ N ≤ 12
• Time Limit: 1 sec