#include <stdio.h>

#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(arr[0]))

double add(double x, double y) { return x + y; }
double sub(double x, double y) { return x - y; }
double mul(double x, double y) { return x * y; }
double div(double x, double y) { return x / y; }

static double (*funcs[])(double, double) = {add, sub, mul, div};

int main() {
  int i = 0;
  while (i < ARRAY_SIZE(funcs)) {
    printf("LolWut?  %f\n", funcs[i++](3.141592, 100500.0));
  } 
}