面試題 08.05. 遞歸乘法

遞歸實現乘法。

class Solution:
    def multiply(self, A: int, B: int) -> int:
        #for i in range(B):
        sum = 0
        if B>1:
            sum = self.multiply(A, B-1) + A
        else:
            sum = A
        return sum