43. Multiply Strings
Given two non-negative integers
num1andnum2represented as strings, return the product ofnum1andnum2, also represented as a string.Note: You must not use any built-in BigInteger library or convert the inputs to integer directly.
Example 1:
Input: num1 = "2", num2 = "3"
Output: "6"Example 2:
Input: num1 = "123", num2 = "456"
Output: "56088"
def multiply(self, num1: str, num2: str) -> str:
d = {
'0':0,'1':1,'2':2,'3':3,'4':4,'5':5,'6':6,'7':7,'8':8,'9':9
}
n1, n2, j = 0, 0, 0
l1, l2 = len(num1)-1, len(num2)-1
for i in num1:
n1 += 10**l1 * d[i]
l1 -= 1
for i in num2:
n2 += 10**l2 * d[i]
l2 -= 1
return str(n1*n2)