I am struggling to solve a hard problem (No. 1526) in LeetCode but only to fail since my codes are rejected again and again by 'time exceeded'.

Short Introduction to the No. 1526 Problem

The image below contains how I planned to solve the problem. Sorry for the bad resolution of it tho.

After I came up with this idea, I thought and still think it's a decent idea so I coded in two ways - recursive one and iterative one.

Recursive

target = [1, 2, 3, 2, 1]
score = 0

def minSubtract(target):
  global score
  if list(set(target)) == set([0]):
    return

  print(f"current arryay is {target}")
  localMin = min(target)
  score += localMin

  newTargets = [ele - localMin for ele in target]


  idx = 0
  Arr = []

  while idx < len(newTargets):
    print(idx)
    if newTargets[idx] != 0: # if nonzero element
      
      subArr = [newTargets[idx]]
      idx_ = idx + 1
      
      while True:

        if (idx_ >= len(newTargets) or (newTargets[idx_] == 0) ):
          idx = idx_
          Arr.append(subArr)
          break
        subArr.append(newTargets[idx_])
        idx_ += 1

    else:
      idx += 1

  print(f"subarrays are {Arr}")

  for subArray in Arr:
    minSubtract(subArray)
  
minSubtract(target)
score

Iterative

score = 0
stack = [target]


while stack:
  curArr = stack.pop()
  localMin = min(curArr)

  if localMin == 0:
    pass

  score += localMin
  SubtractedArr = [ele - localMin for ele in curArr]


  idx = 0
  Arrs = []
  while idx < len(SubtractedArr):

    if SubtractedArr[idx] != 0: # if nonzero element
      
      subArr = [SubtractedArr[idx]]
      idx_ = idx + 1
      
      while True:

        if (idx_ >= len(SubtractedArr) or (SubtractedArr[idx_] == 0) ):
          idx = idx_
          Arrs.append(subArr)
          break
        subArr.append(SubtractedArr[idx_])
        idx_ += 1

    else:
      idx += 1

  for newArr in Arrs:
    stack.append(newArr)

score

However, they both pass 126/128 test cases but still have a runtime issue. I want to know what makes my code have so bad speed or if actually by idea itself sucks.