在python中不使用乘法运算符进行乘法

def multiply(a, b):
    result = 0
    for _ in range(abs(b)):
        result += a
    if b < 0:
        result = -result
    return result

# 示例
print(multiply(3, 4))  # 输出: 12

def multiply_recursive(a, b):
    if b == 0:
        return 0
    elif b > 0:
        return a + multiply_recursive(a, b - 1)
    else:
        return -multiply_recursive(a, -b)

# 示例
print(multiply_recursive(3, 4))  # 输出: 12

def multiply_bitwise(a, b):
    result = 0
    while b != 0:
        if b & 1:
            result += a
        a <<= 1
        b >>= 1
    return result

# 示例
print(multiply_bitwise(3, 4))  # 输出: 12

def multiply_sum(a, b):
    return sum([a for _ in range(abs(b))])

# 示例
print(multiply_sum(3, 4))  # 输出: 12

import numpy as np

def multiply_numpy(a, b):
    return np.multiply(a, b)

# 示例
print(multiply_numpy(3, 4))  # 输出: 12