#include <stdio.h>
#include <conio.h>
#include <math.h>
#include <string.h>

char result[20]; // declares character string result
int type; 
int first = 0;
float mainhold;
float maincur;
int end = 0;
char yesno[10];
int quit = 0;

char Y[] = "Y";
char Yes[] = "Yes";
char YES[] = "YES";
char yes[] = "yes";
char y[] = "y";

char N[] = "N";
char No[] = "No";


int main()
{


void add()
{
             float sumhold; // declares the variable to hold the current total
             float sumcur; // declares the variable to hold the next value being added
             strcpy(result, "Sum");
             if (first == 0)
             {
                       
                       printf(" Enter first number\n");
                       scanf(" %f", &sumhold );
                       mainhold = sumhold;
                       first++;
                       }
                 
                 printf(" Enter number to be added\n");
                 scanf(" %f", &sumcur );
                 
                 if (first == 0)
                 {
                           mainhold = sumcur + sumhold;
                           }
                 else
                 {
                     mainhold = mainhold + sumcur; 
                     } // ends addition section
                     }

void sub()
    {
             float subhold; // declares the variable to hold the current total
             float subcur; // declares the variable to hold the next value being added
             strcpy(result, "Difference");
             if (first == 0)
             {
                       
                       printf(" Enter first number\n");
                       scanf(" %f", &subhold );
                       mainhold = subhold;
                       first++;
                       }
                 
                 printf(" Enter number to subtract\n");
                 scanf(" %f", &subcur );
                 
                 if (first == 0)
                 {
                           mainhold = subcur - subhold;
                           }
                 else
                 {
                     mainhold = mainhold - subcur;
                     }
                     } // ends subtraction section    

void mult()
 {
             float multhold; // declares the variable to hold the current total
             float multcur; // declares the variable to hold the next value being added
             strcpy(result, "Product");
             if (first == 0)
             {
                       
                       printf(" Enter first number\n");
                       scanf(" %f", &multhold );
                       mainhold = multhold;
                       first++;
                       }
                 
                 printf(" Enter number to be multiplied\n");
                 scanf(" %f", &multcur );
                 
                 if (first == 0)
                 {
                           mainhold = multcur * multhold;
                           }
                 else
                 {
                     mainhold = mainhold * multcur;
                     }
                     } // ends multiplication section         

void div()
{
             float divhold; // declares the variable to hold the current total
             float divcur; // declares the variable to hold the next value being added
             strcpy(result, "Quotient");
             if (first == 0)
             {
                       
                       printf(" Enter first number\n");
                       scanf(" %f", &divhold );
                       mainhold = divhold;
                       first++;
                       }
                 
                 printf(" Enter number to divide by\n");
                 scanf(" %f", &divcur );
                 
                 if (divcur != 0)
                 {
                 if (first == 0)
                 {
                           mainhold = divcur / divhold;
                           }
                 else
                 {
                     mainhold = mainhold / divcur;
                     }
                     }
                     else
                     {
                         printf(" Can not divide by zero\n");
                         printf(" Press any key to continue\n\n");
                         getch();  // How I set it to clear everything without using a goto?                        
                         }
                     } // ends division section                     
     

void root()
 {
             float roothold; // declares the variable to hold the current total
             float rootcur; // declares the variable to hold the next value being added
             strcpy(result, "Square root");
             if (first == 0)
             {
                       
                       printf(" Enter first number\n");
                       scanf(" %f", &roothold );
                       mainhold = roothold;
                       first++;
                       }
                 
                 if (first == 0)
                 {
                           mainhold = sqrt(roothold);
                           }
                 else
                 {
                     mainhold = sqrt(mainhold);
                     }
                     } // ends square root section



void expo()
{
float expa;
float base;
float expaend;
int expcount;

      printf( "Enter numerical base\n"); /* asks user to enter numerical base */
      scanf(" %f", &base); /* assigns the variable "base" a value */
      printf( "Enter numerical exponant\n"); /* requests value of exponant */
      scanf(" %f", &expa); /* assigns the variable "expa" a value */

      
      if(first==0)
      {
      first++;

      if ((expa == 0) || (expa == 1)) /* deals with exponants one and zero */
      {
      if (expa == 0) /* deals with something to the zero power */
      {
              (expaend = 1); /* assigns "basenot" to the zero power as having the value of one */
      }
      else {
           (expaend = base); /* assigns "base" to the first power a value of itself */
           }
           }
           else {
                (expaend = base); /* starts end at the value of base */
                for (expcount = 2; expcount <= expa; expcount++) /* from 2 = expcount <= expa, do a loop */
      {
          expaend = (expaend * base);
          }
          }
          printf( "%f to the %f power is %f\n", base, expa, expaend);
          mainhold = expaend;

          }
          
             } // ends exponant section

while (quit == 0)
{
while (end == 0) // begins the main while statement
{


    printf(" Type the number that matches the type of calcuation\n ");
    printf(" 1 Addition\n ");
    printf(" 2 Subtraction\n ");
    printf(" 3 Multiplication\n ");
    printf(" 4 Division\n ");
    printf(" 5 Square Root\n ");
    printf(" 6 Exponants\n ");
    printf(" 7 Fractional Exponants\n ");
    printf(" 8 Exit Program\n "); // Don't forget to change the quit value when adding additional features
    scanf(" %d", &type );
    

    if (type == 1)
    {
       add();
                     } // ends adddition section
                     
    if (type == 2)
{
    sub();
}         
                     
                     
    if (type == 3)
   {
       mult();
       }
                  
                     
                     
    if (type == 4)
    {
             div();
             }

    if (type == 5)
   {
       root();
       }
                     
    if (type == 6) // begins exponant section
    {
             expo();
             }
             
      if (type == 8) // begins quit section
      {
               end++;
               quit++;
               } // ends quit section
             
             if ((type >= 1 && type <= 3) || (type >= 5 && type <= 7)) // Don't forget to modify this when adding additional features
             {
             if ((type >= 1 && type <= 3) || (type <= 5)) // Don't forget to modify this when adding additional features
             {        
             printf(" %s is %f\n", result, mainhold); // prints result for any of the first five except division
             } 
             printf(" Perform additional operation to current number? (Y/N)\n");
             scanf(" %s", &yesno );
             if ((strcasecmp (yesno,N) == 0) || (strcasecmp (yesno,No) == 0))
             {
                                end++;
                                }
                                }
                                } //ends main while statement
             end--;
             first = 0;
             } // ends final while statement
             return 0;
             }