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

typedef enum op {
	ADD,
	SUB,
	MUL,
	DIV,
} op;

struct operation {
	int a, b;
	op o; 
	int (*funcs[2][2])(int, int);
};

int add(int a, int b) {
	return a + b;
}
int sub(int a, int b) {
	return a - b;
}
int mul(int a, int b) {
	return a * b;
}
int Div(int a, int b) {
	return a / b;
}

int runop(struct operation *o) {
	switch (o->o) {
		case ADD: return o->funcs[0][0](o->a, o->b);
		case SUB: return o->funcs[0][1](o->a, o->b);
		case MUL: return o->funcs[1][0](o->a, o->b);
		case DIV: return o->funcs[1][1](o->a, o->b);
	}
	return -1;
}

struct operation *initop(int a, int b, op ope) {
	struct operation *o = malloc(sizeof(struct operation));
	o->a = a;
	o->b = b;
	o->funcs[0][0] = &add;
	o->funcs[0][1] = &sub;
	o->funcs[1][0] = &mul;
	o->funcs[1][1] = &Div;
	o->o = ope;
}

int main() {
	struct operation *o = initop(5, 5, MUL);
	printf("%d\n", runop(o));
}