两个大整数相加，lintcode(655)

nexthunghung

这是lintcode上的一道题目，两个大整数相加，看题目说明，应该是两个用字符串表示的正整数，不能直接转换为整型，不能用内建函数，不知道怎么做了？求大神解答谢谢
http://www.lintcode.com/zh-cn/problem/big-integer-addition/
Given two non-negative integers num1 and num2 represented as string, return the sum of num1 and num2.

注意事项

The length of both num1 and num2 is < 5100.
Both num1 and num2 contains only digits 0-9.
Both num1 and num2 does not contain any leading zero.
You must not use any built-in BigInteger library or convert the inputs to integer directly.

class Solution:
    # @param {string} num1 a non-negative integers
    # @param {string} num2 a non-negative integers
    # @return {string} return sum of num1 and num2
    def addStrings(self, num1, num2):
        # Write your code here

SixPy

模拟竖式计算
注意进位

SixPy

class Solution:
    # @param {string} num1 a non-negative integers
    # @param {string} num2 a non-negative integers
    # @return {string} return sum of num1 and num2
    def addStrings(self, num1, num2):
        # Write your code here
        carry = 0
        maxlen = max(len(num1),len(num2))
        cov_int = lambda s:(b-48 for b in reversed(bytes(s.rjust(maxlen,'0'),'ascii')))
        rslt = []
        for a,b in zip(cov_int(num1),cov_int(num2)):
            carry,n = divmod((a+b+carry),10)
            rslt.append(n)
        if carry>0:
            rslt.append(carry)

        return ''.join(str(i)for i in reversed(rslt))
        

print(Solution().addStrings('999','456'))

nexthunghung

SixPy 发表于 2017-6-22 22:14

Traceback (most recent call last): File "Main.py", line 14, in result = solution.addStrings(num1, num2) File "Solution.py", line 11, in addStrings for a,b in zip(cov_int(num1),cov_int(num2)): File "Solution.py", line 9, in cov_int = lambda s:(b-48 for b in reversed(bytes(s.rjust(maxlen,'0'),'ascii'))) TypeError: str() takes at most 1 argument (2 given) EXITCODE=1

SixPy

nexthunghung 发表于 2017-6-22 22:35
Traceback (most recent call last): File "Main.py", line 14, in result = solution.addStrings(num1,  ...

我这里运行正常
而且那一句没用到 str() ，怎么会提示 str() 出错呢

SixPy

我写的是python3 的代码

你应该是用python2 ，所以有错误

nexthunghung

SixPy 发表于 2017-6-22 23:18
我写的是python3 的代码

你应该是用python2 ，所以有错误

我在电脑上是可以运行，可是copy放到lintcode上就通过不了了

SixPy

nexthunghung 发表于 2017-6-23 10:52
我在电脑上是可以运行，可是copy放到lintcode上就通过不了了

明白原理就行
可能lintcode的后台是py2吧