2357. Make Array Zero by Subtracting Equal Amounts

Problem

You are given a non-negative integer array nums. In one operation, you must:

• Choose a positive integer x such that x is less than or equal to the smallest non-zero element in nums.

• Subtract x from every positive element in nums.

Return **the *minimum* number of operations to make every element in nums equal to **0.

  Example 1:

Input: nums = [1,5,0,3,5]
Output: 3
Explanation:
In the first operation, choose x = 1. Now, nums = [0,4,0,2,4].
In the second operation, choose x = 2. Now, nums = [0,2,0,0,2].
In the third operation, choose x = 2. Now, nums = [0,0,0,0,0].

Example 2:

Input: nums = [0]
Output: 0
Explanation: Each element in nums is already 0 so no operations are needed.

  Constraints:

• 1 <= nums.length <= 100

• 0 <= nums[i] <= 100

Solution (Java)

class Solution {
    public int minimumOperations(int[] nums) {
        Set<Integer> set = new HashSet<>();
        for (int a : nums) {
            if (a > 0) {
                set.add(a);
            }
        }
        return set.size();
    }
}

Explain:

nope.

Complexity:

• Time complexity : O(n).
• Space complexity : O(n).