How to write code for generating random numbers in the C language?

In C language, the rand() function can be used to generate random numbers. This function will return a random integer ranging from 0 to RAND_MAX. To generate random numbers within a specific range, you can use the modulus operator to perform a modulus operation on the return value of the rand() function.

Here is an example code that generates random numbers within a specified range:

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

int main() {
   int lower = 1, upper = 100, count = 5;

   // 使用当前时间作为随机数种子
   srand(time(0));

   printf("随机数：");
   for(int i = 0; i < count; i++) {
      int num = (rand() % (upper - lower + 1)) + lower;
      printf("%d ", num);
   }
   printf("\n");
   
   return 0;
}

The above code will generate five random numbers between 1 and 100 and print them out.

Before using the rand() function, it is necessary to first use the srand() function to set a random number seed. Here, the time(0) function is used to obtain the current time as the seed, to ensure that a different random number sequence is generated each time the program is run.