How to use the random function “rand” in C++?

In C++, you can use the rand function to generate random numbers. The basic steps to use the rand function are as follows:

1. Include header files: Include header files in the program.
2. Set a random seed: At the beginning of the program, set a random seed by calling the srand function. You can use the time function to get the current time as the seed, to ensure that a different random number sequence is generated each time the program is run. Example code:

#include <cstdlib>
#include <ctime>

int main() {
    srand(time(0)); // 设置随机数种子为当前时间
    // ...
    return 0;
}

1. Generate random numbers by calling the rand function, which will return an integer between 0 and RAND_MAX. To narrow down the range of random numbers generated, you can use the modulus operator. Below is an example code:

int randomNumber = rand() % range;

In this case, the range is the range in which you want to generate random numbers. For example, if you want to generate a random number between 0 and 9, you can set the range to be 10.

The complete example code is shown below:

#include <iostream>
#include <cstdlib>
#include <ctime>

int main() {
    srand(time(0)); // 设置随机数种子为当前时间

    int randomNumber = rand() % 10; // 生成一个0到9之间的随机数

    std::cout << "随机数：" << randomNumber << std::endl;

    return 0;
}

The code will generate a random number between 0 and 9 and display it on the screen.