高精度计算1! 2! ....n! c

以下是Python实现高精度计算1! 2! ....n!的代码：

def multiply(num1, num2):
    """
    高精度乘法
    """
    len1, len2 = len(num1), len(num2)
    res = [0] * (len1 + len2)
    for i in range(len1 - 1, -1, -1):
        carry = 0
        for j in range(len2 - 1, -1, -1):
            tmp = int(num1[i]) * int(num2[j]) + carry + res[i + j + 1]
            carry, res[i + j + 1] = divmod(tmp, 10)
        res[i] += carry
    while res[0] == 0 and len(res) > 1:
        res.pop(0)
    return ''.join(map(str, res))

def factorial(n):
    """
    高精度阶乘
    """
    res = '1'
    for i in range(2, n + 1):
        res = multiply(res, str(i))
    return res

# 读取输入文件
with open('factor.in', 'r') as f:
    n = int(f.readline().strip())

# 计算n的阶乘
res = factorial(n)

# 将结果写入输出文件
with open('factor.out', 'w') as f:
    f.write(res)