程序代码：

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

int main(void) {
    const char* numbers = "1223334444";
    srand(time(0));
    printf("%c\n", *((rand() % 10) + numbers));
    return 0;
}

程序代码：

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

int main(void) {
   srand(time(0));
   switch (rand() % 10) {
   case 0:
      printf("1\n");
      break;
   case 1: case 2:
      printf("2\n");
      break;
   case 3: case 4: case 5:
      printf("3\n");
      break;
   case 6: case 7: case 8: case 9:
      printf("4\n");
      break;
   }
   return 0;
}