Watch 10 video solutions for Make Array Elements Equal to Zero, a easy level problem involving Array, Simulation, Prefix Sum. This walkthrough by NeetCodeIO has 15,643 views views. Want to try solving it yourself? Practice on FleetCode or read the detailed text solution.
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:
curr is out of the range [0, n - 1], this process ends.nums[curr] == 0, move in the current direction by incrementing curr if you are moving right, or decrementing curr if you are moving left.nums[curr] > 0:
nums[curr] by 1.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:
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].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 <= 1000 <= nums[i] <= 100i where nums[i] == 0.