<qiyuangong>538_Convert_BST_to_Greater_Tree_1.py
def convertBST( root):
    total = 0
    
    node = root
    stack = []
    while stack or node is not None:
        while node is not None:
            stack.append(node)
            node = node.right
    
        node = stack.pop()
        total += node.val
        node.val = total
    
        node = node.left
    
    return root
def sample_funcname ( var_0 ) :
    var_2 = 0
    var_3 = var_0
    var_4 = [ ]
    while var_4 or var_3 is not None :
        while var_3 is not None :
            var_4.append ( var_3 )
            var_3 = var_3.right
        var_3 = var_4.pop ( )
        var_2 += var_3.val
        var_3.val = var_2
        var_3 = var_3.left
    return var_0
