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

void test1(int a, double b) {
  printf("%d %lf\n", a, b);
}

char test2(int a) {
  return (char) a;
}

double test3(void) {
  return 1.0;
}

int addition(int a, int b) {
  return a + b;
}

int multiplication(int a, int b) {
  return a * b;
}

void main(void) {
  printf("%p\n", test1);
  printf("%p\n", test2);
  printf("%p\n", test3);
  printf("\n");
  void (*f1)(int, double) = test1;
  char (*f2)(int) = test2;
  double (*f3)(void) = test3;
  f1(2, 3.1);
  printf("%c\n", f2(109));
  printf("%lf\n", f3());
  printf("\n");
  int (*operation)(int, int);
  if (rand() % 2 == 0) {
    operation = addition;
  }
  else {
    operation = multiplication;
  }
  printf("%d\n", operation(5, 6));
}