Package g3301_3400.s3354_make_array_elements_equal_to_zero

Class Solution

java.lang.Object

g3301_3400.s3354_make_array_elements_equal_to_zero.Solution

public class Solution
extends Object

3354 - Make Array Elements Equal to Zero.

Easy

You are given an integer array nums.

Start by selecting a starting position curr such that nums[curr] == 0, and choose a movement direction of either left or right.

After that, you repeat the following process:

• If curr is out of the range [0, n - 1], this process ends.
• If nums[curr] == 0, move in the current direction by incrementing curr if you are moving right, or decrementing curr if you are moving left.
• Else if nums[curr] > 0:
  • Decrement nums[curr] by 1.
  • Reverse your movement direction (left becomes right and vice versa).
  • Take a step in your new direction.

A selection of the initial position curr and movement direction is considered valid if every element in nums becomes 0 by the end of the process.

Return the number of possible valid selections.

Example 1:

Input: nums = [1,0,2,0,3]

Output: 2

Explanation:

The only possible valid selections are the following:

• Choose curr = 3, and a movement direction to the left.
  • [1,0,2, 0 ,3] -> [1,0, 2 ,0,3] -> [1,0,1, 0 ,3] -> [1,0,1,0, 3 ] -> [1,0,1, 0 ,2] -> [1,0, 1 ,0,2] -> [1,0,0, 0 ,2] -> [1,0,0,0, 2 ] -> [1,0,0, 0 ,1] -> [1,0, 0 ,0,1] -> [1, 0 ,0,0,1] -> [1 ,0,0,0,1] -> [0, 0 ,0,0,1] -> [0,0, 0 ,0,1] -> [0,0,0, 0 ,1] -> [0,0,0,0, 1 ] -> [0,0,0,0,0].
• Choose curr = 3, and a movement direction to the right.
  • [1,0,2, 0 ,3] -> [1,0,2,0, 3 ] -> [1,0,2, 0 ,2] -> [1,0, 2 ,0,2] -> [1,0,1, 0 ,2] -> [1,0,1,0, 2 ] -> [1,0,1, 0 ,1] -> [1,0, 1 ,0,1] -> [1,0,0, 0 ,1] -> [1,0,0,0, 1 ] -> [1,0,0, 0 ,0] -> [1,0, 0 ,0,0] -> [1, 0 ,0,0,0] -> [1 ,0,0,0,0] -> [0,0,0,0,0].

Example 2:

Input: nums = [2,3,4,0,4,1,0]

Output: 0

Explanation:

There are no possible valid selections.

Constraints:

• 1 <= nums.length <= 100
• 0 <= nums[i] <= 100
• There is at least one element i where nums[i] == 0.

Constructor Summary

Constructors

Constructor	Description
Solution()

Method Summary

Modifier and Type	Method	Description
int	countValidSelections(int[] nums)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Solution

public Solution()

Method Details

countValidSelections

public int countValidSelections(int[] nums)