//import the java input/output library
import java.io.*;


//class that contains the math functions
class MFunctions {

//result variable
double result;

String inData;

//constructor...not much here...
//remnant from the days when the user input was supplied to
//this class as an argument
//MFunctions() {
//}

//addition method
double add(double v1, double v2) {
 
 result = (v1 + v2);
 return result;
}


//subtraction method
double subtract(double v1, double v2) {
 
 result = (v1 - v2);
 return result;
}


//multiplication method
double multiply(double v1, double v2) {
 
 result = (v1 * v2);
 return result;
}


//division method
double divide(double v1, double v2) {
 
 result = (v1 / v2);
 return result;
}


//clear method
double clear(double v1) {
 
 result = v1;
 return result;
}


//square method
double square(double v1) {
 
 result = (v1 * v1);
 return result;
}


//square root method
double sqroot(double v1) {
 
 result = Math.sqrt(v1);
 return result; 
}


//"power of" method
//doesn't quite work right when power is a floating-point input
double power(double v1, double v2, double v3) {
 
 int i = 1;
 
 //get initial input
 //v3 remains as the initial input
 //so that v1 can be accurately calculated
 //increment loop until power is reached
  while (i < v2) {
  v1 = (v1 * v3);
  i++;
  
  }//while loop ends here
 
 result = v1;
 
 return result;
 
  }//"power-of" method ends here


}//MFunctions class ends here






//class containing the "main" method
class FFC {

public static void main(String[] args) throws IOException {
 
 //generic input variable
 String inData, userChoice;
 
 //user-defined input variables
 double initialV, nextV;
 
 double x = 0;
 
 //boolean variable for quitting loop
 boolean sentV = false;
 
 //initiate java IO library
 InputStreamReader isr = new InputStreamReader(System.in);
   BufferedReader br = new BufferedReader(isr);
 
 //instantiate object of "MFunctions" class
 MFunctions mf = new MFunctions();

 //initial user input
   System.out.println("\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n");
   System.out.println("Welcome to the currently expanding calculator simulation!");
   System.out.print("When prompted for a math function choice ");
   System.out.print("please type either: \nthe number of your choice, ");
   System.out.println("\nor the symbol beside the number.");
   System.out.println("\nIf you receive a result of either: ");
   System.out.println("'NaN' or 'infinity'");
   System.out.println("OR repeated calculations reach the UNEXPECTED result of either '1' or '0'");
   System.out.println("Your calculations have exceeded the bounds of the java language.");
 
   System.out.println("\n\nEnter a number.\n\n\n\n\n\n\n\n\n\n\n");
   inData = br.readLine();
   initialV = Double.parseDouble(inData);
   
   //quitting loop 
   while (sentV != true) {
    
    //determine the math function from the user
    System.out.println("\n\n\nChoose a basic math function.\n");
    System.out.println("1. +\t(addition)");
    System.out.println("2. -\t(subtraction)");
    System.out.println("3. *\t(multiplication)");
    System.out.println("4. /\t(division)");
    System.out.println("5. c\t(clear)");
    System.out.println("6. =\t(equals/finished)");
    System.out.println("7. s\t(square)");
    System.out.println("8. sq\t(square root)");
    System.out.println("9. pw\t(power of)");
    System.out.println("\n\n\n\n\n");
    userChoice = br.readLine();
    
    
    //if user chooses to add...
    if (userChoice.trim().startsWith("+") || userChoice.trim().startsWith("1") ) {
   
    //get next number from user
    System.out.println("\n\n" + initialV + " Plus?\n\n");
    inData = br.readLine();
    nextV = Double.parseDouble(inData);    
    //print current value and assign that value to initial value
    //this is repeated in the following...
    System.out.println("\n\n\n\n\n\n\n\n\n\n");
    System.out.println("Current value is: " + mf.add(initialV, nextV) + "\n");
    initialV = mf.add(initialV, nextV);
   
    }//end user add choice
   
    
    //if user chooses to subtract
    if (userChoice.trim().startsWith("-") || userChoice.trim().startsWith("2") ) {
   
    System.out.println("\n\n" + initialV + " Minus?\n\n");
    inData = br.readLine();
    nextV = Double.parseDouble(inData);   
    //see above comment in add choice
    System.out.println("\n\n\n\n\n\n\n\n\n\n");
    System.out.println("\n\nCurrent value is: " + mf.subtract(initialV, nextV) + "\n");
    initialV = mf.subtract(initialV, nextV);
   
    }//end user subtract choice
   
   
    //if user chooses to multiply
    if (userChoice.trim().startsWith("*") || userChoice.trim().startsWith("3") ) {
   
    System.out.println("\n\n" + initialV + " Multiplied by?\n\n");
    inData = br.readLine();
    nextV = Double.parseDouble(inData);   
    //see above comment in add choice
    System.out.println("\n\n\n\n\n\n\n\n\n\n");
    System.out.println("\n\nCurrent value is: " + mf.multiply(initialV, nextV) + "\n");
    initialV = mf.multiply(initialV, nextV);
   
    }//end user multiplication choice
   
    
    //if user chooses to divide
    if (userChoice.trim().startsWith("/") || userChoice.trim().startsWith("4") ) {
   
    System.out.println("\n\n" + initialV + " Divided by?\n\n");
    inData = br.readLine();
    nextV = Double.parseDouble(inData);
    //see above comment in add choice
    System.out.println("\n\n\n\n\n\n\n\n\n\n");
    System.out.println("\n\nCurrent value is: " + mf.divide(initialV, nextV) + "\n");
    initialV = mf.divide(initialV, nextV);
   
    }//end user division choice   
  
    //if user chooses to clear
    if (userChoice.trim().startsWith("c") || userChoice.trim().startsWith("5") ) {
    
    System.out.println("\n\n\n\n\n\n\n\n\n");
    System.out.println("The new initial value is zero.\n\n");
    System.out.println("Enter the new initial value.");
    System.out.println("\n\n\n\n\n");
    inData = br.readLine();
    initialV = Double.parseDouble(inData);
    System.out.println("\n\n\n\n\n\n\n\n\n");
    System.out.println("\n\nCurrent value is: " + mf.clear(initialV) + "\n");
    initialV = mf.clear(initialV);
    
    }//end user clear choice
    
    
    //if user chooses square
   if (userChoice.trim().startsWith("s") || userChoice.trim().startsWith("7") ) {
    System.out.println("\n\n\n\n\n\n\n\n\n\n");
    System.out.println("\n\nCurrent value is: " + mf.square(initialV) + "\n");
    initialV = mf.square(initialV);
    
   }//end user square choice  
   
   
   //if user chooses square root
   if (userChoice.trim().startsWith("sr") || userChoice.trim().startsWith("8") ) {
    System.out.println("\n\n\n\n\n\n\n\n\n\n");
    System.out.println("\n\nCurrent value is: " + mf.sqroot(initialV) + "\n");
    initialV = mf.sqroot(initialV);
    
   }//end user square root choice 
   
   
   //if user chooses "power-of"
   
   final double thirdV = initialV;
   
   if (userChoice.trim().startsWith("pw") || userChoice.trim().startsWith("9") ) {
     System.out.println(initialV + "\n\nTo the power of?");
     inData = br.readLine();
     nextV = Double.parseDouble(inData);
     System.out.println("\n\n\n\n\n\n\n\n\n\n");
     System.out.println("\n\nCurrent value is: " + mf.power(initialV, nextV, thirdV) + "\n");
     initialV = mf.power(initialV, nextV, thirdV);
     
   }//end user "power-of" choice
     
   
  
    //if user chooses to quit
    if (userChoice.trim().startsWith("=") || userChoice.trim().startsWith("6") ) {
   
    sentV = true;
    
    }//end user final quitting choice
       
   
  }//while loop ends here
   
   
   //final value printed on-screen for user
   System.out.println("\n\n\n\n\n\n\n");
   System.out.println("The final result is:\t" + initialV);
   System.out.println("\n\n\n\n\n\n\n");
     
   

  }//main ends here
  
  
}//class ends here

//C standard I/O library
#include <stdio.h>

//creating my own boolean types for clarity
#define true 1
#define false 0

//global variable for dynamic calculations
double dCurrentV = 0;

//function declarations
double add(double x, double y);
double sub(double x, double y);
double mlt(double x, double y);
double div(double x, double y);
int clear(void);

//begin main
int main(void)  
{  
  //user-defined operation choice
  int iOpChoice;
  //boolean do-while loop sentinal value
  int iSentVal = true;
  //user-defined next number choice
  double dNext;
  
  //opening marquee
  printf("\n\n\n\n\n\n\n\n\n\n");
  printf("       ***********************************************\n");
  printf("       *                       *\n");
  printf("       *                       *\n");
  printf("       *                       *\n");
  printf("       *                       *\n");
  printf("       *  The four-function calculator simulation  *\n");
  printf("       *         written in C        *\n");
  printf("       *        b hancock 2004        *\n");
  printf("       *                       *\n");
  printf("       *                       *\n");
  printf("       ***********************************************\n\n\n\n");
  printf("\n\n\n\n\n");
  
clearpoint:;
  printf("\n\n\nFirst number?");
  scanf("%lf", &dCurrentV);
  
  //do=while loop begins here
  do
  {
    
  printf("\n\n\nPlease choose a function from the list\n\n\n");
  printf("1.\tAddition\t\t4.\tDivision\n\n");
  printf("2.\tSubtraction\t\t5.\tClear (Reset)\n\n");
  printf("3.\tMultiplication\t\t6.\tQuit\n\n\n\n");
  
  scanf("%d", &iOpChoice);
  
  //switch starts here
  switch(iOpChoice)
  {
    case 1:
      printf("add?");
      scanf("%lf", &dNext);
      dCurrentV = add(dCurrentV, dNext); 
      printf("\n\n\n\n");
      printf("The current value is %lf", dCurrentV);
      break;
      
    case 2:
      printf("subtract?");
      scanf("%lf", &dNext);
      dCurrentV = sub(dCurrentV, dNext); 
      printf("\n\n\n\n");
      printf("The current value is %lf\n\n\n", dCurrentV);
      break;
      
    case 3:
      printf("multiply by?");
      scanf("%lf", &dNext);
      dCurrentV = mlt(dCurrentV, dNext); 
      printf("\n\n\n\n");
      printf("The current value is %lf\n\n\n", dCurrentV);
      break;
      
    case 4:
      printf("divide by?");
      scanf("%lf", &dNext);
      dCurrentV = div(dCurrentV, dNext);
      printf("\n\n\n\n");
      printf("The current value is %lf\n\n\n", dCurrentV);
      break;
      
    case 5:
      clear();
      goto clearpoint;
      break;  
      
    case 6:
      iSentVal = false;
      break;
    
    default:
      printf("Invalid input\n");
      break;    
      
    } //switch ends here
  }//do-while loop ends here
  while(iSentVal != false);
  return 0;
}//main ends here
  
//function definitions  
double add(double x, double y)
{
  double result;  
  result = (x + y);
  return result;
}

double sub(double x, double y)
{
  double result;  
  result = (x - y);
  return result;
}

double mlt(double x, double y)
{
  double result;  
  result = (x * y);
  return result;
}

double div(double x, double y)
{
  double result;  
  result = (x / y);
  return result;
}

int clear(void)
{
  dCurrentV = 0;
  return dCurrentV;
}
//program ends here

#include <iostream>

using namespace std;

class Func
{
  public:
    
    Func(double firstV);
    ~Func();
    double add(double cValue);
    double sub(double cValue);
    double mlt(double cValue);
    double div(double cValue);
    int clr(double cValue);
    
  private:
    
    double cValue;
  };
  
  
  
  
  
Func::Func(double firstV)
{
  cValue = firstV;
}    

Func::~Func()
{
}

double Func::add(double cValue)
{
  double y;
  cout<<"\n\n\nAdd?\n\n\n\n"<<endl;
  cin>>y;
  cValue = (cValue + y);
  return cValue;
}

double Func::sub(double cValue)
{
  double y;
  cout<<"\n\n\nSubtract?\n\n\n\n"<<endl;
  cin>>y;
  cValue = (cValue - y);
  return cValue;
}

double Func::mlt(double cValue)
{
  double y;
  cout<<"\n\n\nMultiply by?\n\n\n\n"<<endl;
  cin>>y;
  cValue = (cValue * y);

  return cValue;
}

double Func::div(double cValue)
{
  double y;
  cout<<"\n\n\nDivided by?\n\n\n\n"<<endl;
  cin>>y;
  cValue = (cValue / y);
  return cValue;
}             

int Func::clr(double cValue)
{
  cValue = 0;
  return cValue;
}


  


int main()
{
  cout<<"\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n"<<endl;
  cout<<"        *****************************************************\n";
  cout<<"        *                          *\n";
  cout<<"        *                          *\n";
  cout<<"        *                          *\n";
  cout<<"        *                          *\n";
  cout<<"        *   The four-function calculator simulation   *\n";
  cout<<"        *         written in C++          *\n";
  cout<<"        *         b hancock 2004          *\n";
  cout<<"        *                          *\n";
  cout<<"        *                          *\n";
  cout<<"        *                          *\n";
  cout<<"        *                          *\n";
  cout<<"        *****************************************************\n";
  
  int uChoice1;
  double cValue;
  bool cont = true;
  
  cout<<"\n\n\nInitial value?\n\n\n\n"<<endl;
  cin>>cValue;
  cout<<"\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n"<<endl;
  cout<<"The current value is "<<cValue<<"\n\n"<<endl;
  
  Func ffc(cValue);
  
  do
  {    
    cout<<"\n\nPick a function.\n\n"<<endl;
    cout<<"1.\tAddition\t4.\tDivision\n\n"<<endl;
    cout<<"2.\tSubtraction\t5.\tClear\n\n"<<endl;
    cout<<"3.\tMultiplication\t6.\tQuit.\n\n"<<endl;
    cin>>uChoice1;
    
    switch (uChoice1)
    {
      case 1:
        cValue = ffc.add(cValue);
        cout<<"\n\n\n\n\n\n\n\n\n\n";
        cout<<"The current result is "<<cValue<<"\n\n\n"<<endl;
        break;
        
      case 2:
        cValue = ffc.sub(cValue);
        cout<<"\n\n\n\n\n\n\n\n\n\n";
        cout<<"The current result is "<<cValue<<"\n\n\n"<<endl;
        break;
        
      case 3:
        cValue = ffc.mlt(cValue);
        cout<<"\n\n\n\n\n\n\n\n\n\n";
        cout<<"The current result is "<<cValue<<"\n\n\n"<<endl;
        break;
        
      case 4:
        cValue = ffc.div(cValue);
        cout<<"\n\n\n\n\n\n\n\n\n\n";
        cout<<"The current result is "<<cValue<<"\n\n\n"<<endl;
        break;       
        
      case 5:
        cValue = ffc.clr(cValue);
        cout<<"\n\n\n\n\n\n\n\n\n\n";
        cout<<"The value is now cleared to "<<cValue<<"\n\n\n"<<endl;
        break;
        
      case 6:
        cont = false;
        break;  
        
      default:
        cout<<"\n\n\n\nInvalid input, please re-enter.\n\n";
        continue; 
    }     
  }while(cont == true);   
  
  return 0;
}

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

#define UNARY 0 /* Offset into actions for unary words */
#define BINARY 6 /* Offset into actions for binary words */
#define ACLEN 17 /* Total number of actions */
#define UNLEN 6 /* Total number of unary words */
#define BILEN 11 /* Total number of binary words */

static const char *actions[] = {
 ".", "sqrt", "sq", "not", "abs", "log",
 "+", "-",  "*", "/",  "mod", "pow",
 "<", "=",  ">", "and", "or",
};

static long int stack[1024];
static int top = 0;

static void eval ( void );
static void gather ( void );
static void process ( const char *action );
static void do_unary ( const char *action );
static void do_binary ( const char *action );
static void die ( const char *msg );

static int is_valid ( const char *action, size_t offset, size_t limit );

int main ( void )
{
 while ( 1 )
  eval();
}

void eval ( void )
{
 gather();
 puts ( " ok" );
}

void gather ( void )
{
 char buffer[BUFSIZ];
 char *action;
 char *end;

 if ( fgets ( buffer, sizeof buffer, stdin ) == NULL )
  die ( "Input error" );

 for ( action = strtok ( buffer, " \t\n" );
  action != NULL; action = strtok ( NULL, " \t\n" ) )
 {
  long int number;

  /* Process a number or an action */
  number = strtol ( action, &end, 0 );
  if ( end > action )
   stack[top++] = number;
  else if ( is_valid ( action, 0, ACLEN ) )
   process ( action );
  else if ( strcmp ( action, "bye" ) == 0 )
   exit ( EXIT_SUCCESS );
  else
   die ( "Input error" );
 }
}

void process ( const char *action )
{
 if ( is_valid ( action, UNARY, UNLEN ) )
  do_unary ( action );
 else if ( is_valid ( action, BINARY, BILEN ) )
  do_binary ( action );
}

void do_unary ( const char *action )
{
 long int result = 0;
 long int a;

 if ( top == 0 )
  die ( "Stack underflow" );
 a = stack[--top];

 if ( strcmp ( action, "." ) == 0 ) {
  printf ( "%ld ", a );
  fflush ( stdout );
  return;
 }
 else if ( strcmp ( action, "not" ) == 0 )
  result = !a;
 else if ( strcmp ( action, "sqrt" ) == 0 )
  result = (long int)sqrt ( a );
 else if ( strcmp ( action, "sq" ) == 0 )
  result = a * a;
 else if ( strcmp ( action, "abs" ) == 0 )
  result = abs ( a );
 else if ( strcmp ( action, "log" ) == 0 )
  result = (long int)log ( a );
 else
  die ( "Invalid format" );

 stack[top++] = result;
}

void do_binary ( const char *action )
{
 long int result = 0;
 long int a, b;

 if ( top < 2 )
  die ( "Stack underflow" );
 b = stack[--top];
 a = stack[--top];

 if ( action[0] == '+' )
  result = a + b;
 else if ( action[0] == '-' )
  result = a - b;
 else if ( action[0] == '*' )
  result = a * b;
 else if ( action[0] == '/' ) {
  if ( b == 0 )
   die ( "Division by zero" );
  result = a / b;
 }
 else if ( strcmp ( action, "mod" ) == 0 ) {
  if ( b == 0 )
   die ( "Division by zero" );
  result = a % b;
 }
 else if ( strcmp ( action, "pow" ) == 0 )
  result = (long int)pow ( a, b );
 else if ( action[0] == '<' )
  result = a < b;
 else if ( action[0] == '=' )
  result = a == b;
 else if ( action[0] == '>' )
  result = a > b;
 else if ( strcmp ( action, "and" ) == 0 )
  result = a && b;
 else if ( strcmp ( action, "or" ) == 0 )
  result = a || b;
 else
  die ( "Invalid format" );

 stack[top++] = result;
}

int is_valid ( const char *action, size_t offset, size_t limit )
{
 size_t i;

 for ( i = offset; i < limit + offset; i++ ) {
  if ( strcmp ( action, actions[i] ) == 0 )
   return 1;
 }

 return 0;
}

void die ( const char *msg )
{
 fprintf ( stderr, "%s\n", msg );
 exit ( EXIT_FAILURE );
}

7 - 4

7 4 - .
3 ok

( 7 - 4 ) * 5

7 4 - 5 * .
15 ok

7 4 -
 ok
5 *
 ok
.
15 ok