Day 22

#3354.make-array-elements-equal-to-zero:-

class Solution:
    def countValidSelections(self, nums: List[int]) -> int:
        n = len(nums)
        
        def simulate(start, direction):
            arr = nums[:]  
            curr = start
            dirn = direction 
            
            while 0 <= curr < n:
                if arr[curr] == 0:
                    curr += dirn
                else:
                    arr[curr] -= 1
                    dirn *= -1
                    curr += dirn
            
            return all(x == 0 for x in arr)
        
        count = 0
        for i in range(n):
            if nums[i] == 0:
                
                if simulate(i, 1): 
                    count += 1
                if simulate(i, -1):  
                    count += 1
        return count