Max Sum of a Pair With Equal Sum of Digits

arrayhash tablesorting

Problem Statement

You are given a 0-indexed array nums consisting of positive integers. You can choose two indices i and j , such that i != j , and the sum of digits of the number nums[i] is equal to that of nums[j] .

Return the maximum value of nums[i] + nums[j] that you can obtain over all possible indices i and j that satisfy the conditions. If no such pair of indices exists, return -1.

Examples

Example 1

Input: nums = [18,43,36,13,7]
Output: 54
The pairs (i, j) that satisfy the conditions are:
- (0, 2), both numbers have a sum of digits equal to 9, and their sum is 18 + 36 = 54.
- (1, 4), both numbers have a sum of digits equal to 7, and their sum is 43 + 7 = 50.
So the maximum sum that we can obtain is 54.

Example 2

Input: nums = [10,12,19,14]
Output: -1
There are no two numbers that satisfy the conditions, so we return -1.

Constraints

1 <= nums.length <= 10 ^5

1 <= nums[i] <= 10 ^9

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Medium

Difficulty

Topic Info

ModuleDSA

CategoryArray

Sub-topicHash Table