เครื่องคิดเลขอย่างง่าย

#include <stdio.h>
int main(void) {
    int left = 12, right = 4, result = 0; char operation = '*';
    // Select the calculation from the operator.
    switch (operation) { case '+': result = left + right; break; case '-': result = left - right; break; case '*': result = left * right; break; case '/': result = left / right; }
    printf("%d %c %d = %d\n", left, operation, right, result);
}

#include <iostream>
int main() {
    int left = 12, right = 4, result = 0; char operation = '*';
    // Select the calculation from the operator.
    switch (operation) { case '+': result = left + right; break; case '-': result = left - right; break; case '*': result = left * right; break; case '/': result = left / right; }
    std::cout << left << ' ' << operation << ' ' << right << " = " << result << '\n';
}