[DAY 04] 계산기 프로그램 구현

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
 
void main()
{
    int num1, num2;
    char oper;
 
    printf("Enter the 1st number : ");
    scanf("%d", &num1);
    printf("Enter operator : ");
    scanf("%c", &oper);
    printf("Enter the 2nd number : ");
    scanf("%d", &num2);
 
    printf("%d %c %d = %d \n", num1, oper, num2, num1 + num2);
}

operator의 문제점

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
 
int main(void)
{
    int x, y;
    char oper;
    char select;
 
    do {
        printf("Input the 1st value : ");
        scanf("%d", &x);
 
        printf("Input operator(+, -, *, /) : ");
        rewind(stdin);
        scanf("%c", &oper);
 
        printf("Input the 2nd value : ");
        scanf("%d", &y);
 
        switch (oper)
        {
        case '+':
            printf("result = %d %c %d = %d \n", x, oper, y, x + y);
            break;
        case '-':
            printf("result = %d %c %d = %d \n", x, oper, y, x - y);
            break;
        case '*':
            printf("result = %d %c %d = %d \n", x, oper, y, x * y);
            break;
        case '/':
            printf("result = %d %c %d = %.2f \n", x, oper, y, (float)x / y);
            break;
        default:
            puts("You entered wrong operator!");
            break;
        }
 
        printf("Do you want to continue? : ");
        rewind(stdin);
        scanf("%c", &select);
    } while (select == 'Y' || select == 'y');
 
    return 0;
}