Given two non-negative integers num1 and num2 represented as strings, return the product of num1 and num2.
Note:
- The length of both
num1andnum2is < 110. - Both
num1andnum2contains only digits0-9. - Both
num1andnum2does not contain any leading zero. - You must not use any
built-in BigInteger libraryorconvert the inputs to integer directly.
- 利用[]int{}记录中间计算过程,此时不考虑进位,例如,"123" 和 "65" 的记录为 []int{6,17,28,15}
- 统一处理进位,记录变为[]int{7,9,9,5}
- 转换为string,返回
细节见程序注释。