#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <stddef.h>

#define OP1 10
#define OP2 5

int add(int op1, int op2)
{
	return op1 + op2;
}

int sub(int op1, int op2)
{
	return op1 - op2;
}

int div(int op1, int op2)
{
	return op1 / op2;
}

int mul(int op1, int op2)
{
	return op1 * op2;
}

/*
 * Note: This function does not account for negative powers
 */
int myPow(int op1, int op2)
{
	int total = 1;
	for(int i = 0; i < op2; i++)
	{
		total *= op1;
	}
	return total;
}

int main(void)
{
	int (*operations[5])(int, int) = {add, sub, div, mul, myPow};
	const char* loopkupTable = "+-/*^";
	
	while(true)
	{
		int opcode = getchar();
		char* opStr = strchr(loopkupTable, opcode);
		if (opStr == NULL)
		{
			printf("Opcode not in table.\n");
		}
		else
		{
			ptrdiff_t chosenOperaton = opStr - loopkupTable;
			printf("Performing operation %c with ops %d and %d. ", *opStr, OP1, OP2);
			printf("Output is %d.\n", operations[chosenOperaton](OP1, OP2));
		}
		getchar();
	}
	
	return 0;
}