s = "A(BB(CC))"
#    012345678
 
 
def build_tree(s, root = {"children": [], "l": 0}, i = 0, j = 0):
  if i == len(s):
    return (root, i)
 
  if s[i] == ")":
    root["r"] = j #root["l"] + 2 * (j - root["l"] + 1)
    return (root, i + 1)
 
  cs = root["children"]
 
  if s[i] == "(":
    if cs and isinstance(cs[-1], list):
      cs[-1][1] = i - 1
      cs[-1][3] = j
    child, ii = build_tree(s, {"children": [], "l": j}, i+1, j)
    root["r"] = child["r"]
    root["children"].append(child)
    return build_tree(s, root, ii, root["r"] + 1)
 
  if not cs or not isinstance(cs[-1], list):
    root["children"].append([i, None, j, None])
 
  root["r"] = j
  return build_tree(s, root, i + 1, j + 1)
 
 
print(build_tree(s))

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