Max Pair Sum in an Array(LeetCode 2815):

Problem

You are given an integer array nums. You have to find the maximum sum of a pair of numbers from nums such that the largest digit in both numbers is equal.

For example, 2373 is made up of three distinct digits: 2, 3, and 7, where 7 is the largest among them.

Return the maximum sum or -1 if no such pair exists.

 

Example 1:

Input: nums = [112,131,411]

Output: -1

Explanation:

Each numbers largest digit in order is [2,3,4].

Example 2:

Input: nums = [2536,1613,3366,162]

Output: 5902

Explanation:

All the numbers have 6 as their largest digit, so the answer is 2536 + 3366 = 5902.

Example 3:

Input: nums = [51,71,17,24,42]

Output: 88

Explanation:

Each number's largest digit in order is [5,7,7,4,4].

So we have only two possible pairs, 71 + 17 = 88 and 24 + 42 = 66.

 

Constraints:

  • 2 <= nums.length <= 100
  • 1 <= nums[i] <= 104