<doocs>0357.Count Numbers with Unique Digits_1.py
def countNumbersWithUniqueDigits( n: int) -> int:
    if n == 0:
        return 1
    if n == 1:
        return 10
    ans, cur = 10, 9
    for i in range(n - 1):
        cur *= 9 - i
        ans += cur
    return ans
def sample_funcname ( var_0 : int ) -> int :
    if var_0 == 0 :
        return 1
    if var_0 == 1 :
        return 10
    var_5 , var_7 = 10 , 9
    for var_9 in range ( var_0 - 1 ) :
        var_7 *= 9 - var_9
        var_5 += var_7
    return var_5
