Php-interview questions, with minimal iterations, transforms all elements of the array to mean (balanced)

PHP Surface Test Algorithm Array

Input: Array, all values are non-negative integers
Goal: Make each value of the array the average of all values and the fewest iterations by transformation
Transformation method: One value itself minus one, so that it is adjacent to the left or next to the right side of the value plus one. The first value of an array can only pass 1 to the right, and the last one passes 1 to the left. All values in the array during the transformation cannot be negative.
Example 1:
Input: [0, 3, 3]
First time: [1, 2, 3] [1, 3, 2]
Second time: [2, 2, 2]
Example 2
[2, 4, 6, 2, 1]
[3, 3, 5, 2, 2]
[3, 3, 4, 2, 3]
[3, 3, 3, 3, 3]
Example 3
[1, 0, 7, 0]
[1, 1, 6, 0]
[2, 1, 5, 0]
[2, 2, 4, 0]
[2, 2, 3, 1]
[2, 2, 2, 2]
Is there any good algorithm to solve this problem, the example is not the only solution. Ask for ideas, implemented in PHP.

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