// 03-calc.cpp : simple calculator with four functions

import std;

using namespace std;

int main() {

int r{}, x{}, y{};

char op{};

cout << "Please enter a calculation (number op number, op is one of +-*/):\n";

cin >> x >> op >> y;

switch (op) {

case '+':

r = x + y;

break;

case '-':

r = x - y;

break;

case '*':

r = x * y;

break;

case '/':

if (y) {

r = x / y;

}

else {

cerr << "Error: divide by zero.\n";

}

break;

default:

cerr << "Error: invalid op.\n";

break;

}

cout << "Result: " << r << '\n';

}