<garvit244>98_1.py
def isValidBST( root):
    if not root:
        return True
    
    stack, result = [], []
    while stack or root:
        if root:
            stack.append(root)
            root = root.left
        else:
            root = stack.pop()
            result.append(root.val)
            root = root.right
    
    previous = result[0]
    for index in range(1, len(result)):
        if previous >= result[index]:
            return False
        previous = result[index]
    return True
def sample_funcname ( var_0 ) :
    if not var_0 :
        return True
    var_2 , var_3 = [ ] , [ ]
    while var_2 or var_0 :
        if var_0 :
            var_2.append ( var_0 )
            var_0 = var_0.left
        else :
            var_0 = var_2.pop ( )
            var_3.append ( var_0.val )
            var_0 = var_0.right
    var_10 = var_3 [ 0 ]
    for var_14 in range ( 1 , len ( var_3 ) ) :
        if var_10 >= var_3 [ var_14 ] :
            return False
        var_10 = var_3 [ var_14 ]
    return True
