Maximize value obtained in Array by jumping to the next consecutive greater

Given an array arr[] of size N, the task is to find the maximum value that can be obtained by following the below conditions:

Select any element (say k) from the array and increase all other elements by 1.
In the next step, jump only to the index with a value k+1.
In the end, you are at the maximum value.

Examples:

Input: N = 4, arr[] ={1, 2, 1, 3}
Output: 3
Explanation: If started from index 0 with a height of 1 unit, then,
the new value of array will be [1, 3, 2, 4].
Then jump to the index with (1+1 = 2) ie 2nd index,
The updated values are [2, 4, 2, 5]. Cannot be at the maximum value at end
The first chosen value was 3 at index 3.
The updated values are [2, 3, 2, 3]. Max achieved -3. Hence ans = 3;

Input: N = 4, arr[]={1, 2, 3, 3}
Output: 4

Approach: The problem can be solved based on the following observation:

On observation, we can realize that for reaching maximum height we have two options

Directly selecting the maximum heighted podium initially available.

Choosing all the elements (say total y) with same value (say x). So highest number that can be reached is (x + y – 1).

Follow the below steps to solve the problem:

Sort the array in increasing order.
Seek for the span of the same value elements and get the maximum value that can be achieved from that span using the above idea.
Perform this for all available spans and store the maximum.
Return the maximum as the required answer.

Below is the implementation of the above approach.