برنامج الآلة الحاسبة

#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
void main()
{
int x,y,z;
char ch,op;
clrscr();
printf("\nMain Menu\n");
printf("1. (+)\n");
printf("2. (-)\n");
printf("3. (*)\n");
printf("4. (/)\n");
printf("5. (exit)\n");
printf("\nplease enter your choice:");
ch=getch();
printf("\n enter two numbers:");
scanf("%d%d",&x,&y);
switch(ch){
case '1':
z=x+y;
op='+';
break;
case '2':
z=x-y;
op='-';
break;
case '3':
z=x*y;
op='*';
break;
case '4':
z=x/y;
op='/';
break;
case '5':
printf("\n press any key to exit");
getch();
exit(0);
default:printf("\n invaild operation");
}
printf("%d%c%d=%d",x,op,y,z);
getch();
}