今日头条测试开发的编程面试题---生成随机数

Summary: Generating Random Numbers from 0 to 1000 Using Only 0 and 1

The algorithm described outlines a method for generating random numbers between 0 and 1000 using only the digits 0 and 1, mimicking a binary system.

Generating Binary Numbers:

• The process starts by initializing an empty string variable binary_string to hold the binary number.
• In a loop, the algorithm randomly generates a 0 or 1 and appends it to binary_string. This step is repeated 10 times to create a 10-digit binary number.

Converting to Decimal Numbers:

• Once a 10-digit binary number is generated, it is converted to a decimal number using Python's int(binary_string, 2) function.

Range Check:

• If the decimal number is less than or equal to 1000, it is considered valid and returned as the random number.
• If the decimal number is greater than 1000, the algorithm restarts to generate a new random number until it gets a number within the 0 to 1000 range.

The algorithm leverages the properties of binary numbers to ensure a uniformly distributed range of integers between 0 and 1023. By checking the generated number is within the desired range, it guarantees that the random number falls between 0 and 1000.

Python Code:

The provided Python code implements the above algorithm using a while loop and the random.randint(0, 1) function to generate the binary digits. It then converts the binary string to a decimal number and checks if it lies within the required range, repeating the process if necessary.