/*   
     File:   Example1.c
     Author: Jesse Demarco
     Date:   Feb. 22, 2007

     Description:  This program prompts the user to enter a number and an operator.
                   The number entered is used in the calculation specified by the
                   operator. When the letter E is entered as the operator, the program 
                   ends.  
*/

#include <stdio.h>
#include <ctype.>
#include <stdlib.>
#include <string.>

int main (void)
{   
    char oper;   /*input character*/
    float i = 0;     /*input number*/
    float set = 0;     /*Set Number */
    int num;
    
    printf("Begin Calculations \n"); 
    /* Loop runs until the letter E is inputed */
    do{
    scanf("%f %c", &i, &oper);
    oper = toupper(oper); /* set as uppercase letter */
    
    /* Switch statement to choose correct operation */
    switch( oper )
     {
        case 'S':
             set = i;
              printf( "= %f \n" , set);
              break;
        case '+' :
             set += i;
              printf( "= %f \n" , set);
              break;
        case '-' : 
             set -= i;
             printf( "= %f \n" , set);
             break;
        case '/' : 
             if (!i == 0){
             set /= i;
             printf( "= %f \n" , set);
             }
             else
             printf( "cannot divide by zero, undefined \n" );
             break;
        case '*' : 
             set *= i;
             printf( "= %f \n" , set);
             break;   
        case 'E' : 
             printf( "= %f \n" , set);
             printf( "\n End of calculations. \n" );
             break;         
        default  : 
             printf( "You did not enter a valid operator, try again. \n" );
             break;
     }		
}while(!(oper == 'E'));


return 0; 
}