one_plus

#coding:utf-8
'''
Created on 2017-9-22

@author: 劉帥
'''
def plus_1(num_arr):
    #print enumerate(num_arr)
    #print list(enumerate(num_arr))
    #print reversed(list(enumerate(num_arr)))
    for idx, digit in reversed(list(enumerate(num_arr))):
        print idx,digit
        num_arr[idx] = (num_arr[idx] + 1) % 10
        if num_arr[idx]:
            return num_arr
    return [1] + num_arr #每位數字全爲0的情況

def plus_one(digits):
    n = len(digits)
    for i in range(n-1, -1, -1):#逆序
        print i
        if digits[i] < 9:
            digits[i] += 1
            return digits
        digits[i] = 0
    digits.insert(0, 1)
    return digits

print plus_1([9,9,9,9])
print plus_one([9,9,9,9])