Challenge 2

Challenge2.c

/**
 * @author:     Pat Hawks
 * Created on:  Mar 06, 2015
 * Source File: Challenge2.c
 *
 * To compile:
 *    gcc Challenge2.c -Wall -o Challenge2
 */

#include <stdio.h>
#include <math.h>
#ifndef EXIT_SUCCESS
#define EXIT_SUCCESS 0
#endif

#define CELSIUS 'C'
#define FAHRENHEIT 'F'
#define UNKNOWN '?'

typedef struct Temperature {
    double degrees;
    char system;
} Temperature;

/**
 * Convert a temperature Fahrenheit <=> Celsius
 *
 * @param tempIn        Input temperature
 * @param tempOut       Placeholder for Output temperature
 */
void convertTemp( Temperature *tempIn, Temperature *tempOut ) {
    switch( tempIn->system ) {
        case FAHRENHEIT:
            tempOut->degrees = (tempIn->degrees - 32) * 5/9;
            tempOut->system = CELSIUS;
            return;
        case CELSIUS:
            tempOut->degrees = tempIn->degrees * 9/5 + 32;
            tempOut->system = FAHRENHEIT;
            return;
        default:
            tempOut->degrees = NAN;
            tempOut->system = UNKNOWN;
            return;
    }
}

int main( void ) {
    const char *PROMPT_STRING = "Enter the temperature and scale (eg. 80.0F): ";
    const char *SCAN_FORMAT = "%lf %1[CcFf] *[ \n\t]";
    const char *OUTPUT_FORMAT = "%.1lf°%1c == %.1lf°%1c\n";
    Temperature tempIn;
    Temperature tempOut;

    int scannedArgs;
    do {
        printf( "%s", PROMPT_STRING );
        scannedArgs = scanf( SCAN_FORMAT, &(tempIn.degrees), &(tempIn.system) );
        while ( getchar() != '\n' ) {} // Flush input buffer
        tempIn.system &= 0xDF;         // Char to Uppercase
    } while ( scannedArgs != 2 );

    convertTemp( &tempIn, &tempOut );
    printf(
        OUTPUT_FORMAT,
        tempIn.degrees,  tempIn.system,
        tempOut.degrees, tempOut.system
    );

    return EXIT_SUCCESS;
}

Challenge2.cpp

/**
 * @author:     Pat Hawks
 * Created on:  Mar 06, 2015
 * Source File: Challenge2.c
 *
 * To compile:
 *    g++ Challenge2.cpp -Wall -std=c++11 -o Challenge2
 */

#include <cmath>
#include <iomanip>
#include <iostream>
#include <string>
#if __cplusplus < 201103L
#warning You must compile this program with -std=c++11
#endif
#ifndef EXIT_SUCCESS
#define EXIT_SUCCESS 0
#endif

class Temperature {
public:
    static const char CELSIUS = 'C';
    static const char FAHRENHEIT = 'F';
    static const char UNKNOWN = '?';
    Temperature convertTemp() const;
    bool isValid() const;
    friend std::ostream& operator<<( std::ostream&, const Temperature& );
    friend std::istream& operator>>( std::istream&, Temperature& );
    friend bool operator==( const Temperature&, const Temperature& );
private:
    double degrees;
    char system;
};

int main( void ) {
    const char *PROMPT = "Enter the temperature and scale (eg. 80.0F): ";
    const char *EQUALS = " == ";
    Temperature tempIn;
    Temperature tempOut;

    do {
        std::cout << PROMPT;
        std::cin >> tempIn;
    } while ( !tempIn.isValid() );

    tempOut = tempIn.convertTemp();
    std::cout << std::setprecision(1) << std::fixed
              << tempIn  << EQUALS << tempOut << std::endl;

    return EXIT_SUCCESS;
}

/**
 * Converts a character to uppercase
 * This happens at compile time, so there is no performance penalty!
 *
 * @param  ch character to convert
 * @return uppercase equivilant of ch
 */
constexpr char ucase( char ch ){
    return ch & 0xDF;
}

/**
 * Converts a character to lowercase
 *
 * @param  ch character to convert
 * @return lowercase equivilant of ch
 */
constexpr char lcase( char ch ){
    return ch | 0x20;
}

/**
 * Convert a temperature Fahrenheit <=> Celsius
 *
 * @return Converted temperature object
 */
Temperature Temperature::convertTemp( void ) const {
    Temperature tempOut;
    switch( system ) {
        case FAHRENHEIT:
            tempOut.degrees = (degrees - 32) * 5/9;
            tempOut.system = CELSIUS;
            break;
        case CELSIUS:
            tempOut.degrees = degrees * 9/5 + 32;
            tempOut.system = FAHRENHEIT;
            break;
        default:
            tempOut.degrees = NAN;
            tempOut.system = UNKNOWN;
    }
    return tempOut;
}

/**
 * @return true if object contains a valid Temperature, otherwise false
 */
bool Temperature::isValid( void ) const {
    return system == FAHRENHEIT || system == CELSIUS;
}

std::ostream& operator<<( std::ostream &out, const Temperature &temp ) {
    out << temp.degrees << "°" << temp.system;
    return out;
}

std::istream& operator>>( std::istream &in, Temperature &temp ) {
    const size_t NOT_FOUND = std::string::npos;
    std::string input;
    size_t *nextChar = nullptr;

    std::getline( in, input );
    try {
        temp.degrees = stod( input, nextChar );
    } catch(...) {
        goto TemperatureInputFail; // I know, I know
    }

    if (
         input.find_first_of(ucase(Temperature::FAHRENHEIT))!=NOT_FOUND
      || input.find_first_of(lcase(Temperature::FAHRENHEIT))!=NOT_FOUND
    ) {
        temp.system = Temperature::FAHRENHEIT;
    } else if (
         input.find_first_of(ucase(Temperature::CELSIUS))!=NOT_FOUND
      || input.find_first_of(lcase(Temperature::CELSIUS))!=NOT_FOUND
    ) {
        temp.system = Temperature::CELSIUS;
    } else {
        TemperatureInputFail:
        temp.degrees = NAN;
        temp.system = Temperature::UNKNOWN;
    }

    return in;
}

bool operator==( const Temperature &a, const Temperature &b ) {
    if ( a.system == b.system )
        return a.degrees == b.degrees;
    else
        return a == b.convertTemp();
}

Challenge2.js

/**
 * @author:     Pat Hawks
 * Created on:  Mar 06, 2015
 * Source File: Challenge2.js
 *
 * See this in action:
 *     http://student.pathawks.com/AICSC/Challenges/20150306/
 */
"use strict";

window.onload=function(){
    var formatNum = function( degrees, system ) {
        var FAHRENHEIT = "F";
        var CELSIUS = "C";
        var tempOut;

        switch( system ) {
            case FAHRENHEIT:
                tempOut = ((degrees - 32) * 5/9).toFixed(1) + "°" + CELSIUS;
                break;
            case CELSIUS:
                tempOut = (degrees * 9/5 + 32).toFixed(1) + "°" + FAHRENHEIT;
                break;
            default:
                return false;
        }
        return tempOut;
    };

    document.getElementsByTagName("form")[0].onsubmit=function(){
        var a=document.getElementById("tempin").value,
            b=document.getElementById("system").value,
            c=formatNum( a, b ),
            d=(+a).toFixed(1) + "°" + b + " == " + c; // (+a) to cast as double
        if ( !!a && !isNaN(+a) ) { // Not empty and can be cast as a double
            document.getElementById("outnum").innerHTML=d,
            document.body.className="displaying-output";
        } else {
            document.getElementById("tempin").value="";
            document.body.className="waiting-for-input";
        }
        return false;
    }
};

Challenge2.S

/**
 * @author:     Pat Hawks
 * Created on:  Mar 06, 2015
 * Source File: Challenge2.s
 *
 * To compile:
 *    gcc Challenge2.s -o Challenge2
 */

.code32
    .equ    _main, main
    .equ    printf, _printf
    .equ    scanf, _scanf
    .equ    STACK_SPACE, 28
    .equ    tempA,       16
    .equ    tempB,        4
    .equ    tempASys,    24
    .equ    tempBSys,    12
    .equ    ptr2,         8
    .equ    ptr1,         4
    .equ    format,       0
    .equ    UPPERCASE, 0xDF
    .equ    C,          'C'
    .equ    F,          'F'
    .global _main
.data
PROMPT_STRING:
    .asciz "Enter the temperature and scale (eg. 80.0F): "
FORMAT_STRING:
    #ifdef WIN32
    .asciz "%.1lf\370%1c == %.1lf\370%1c\n"
    #else
    .asciz "%.1lf°%1c == %.1lf°%1c\n"
    #endif
INPUT_STRING:
    .asciz "%lf%1c"
NINE_FIFTHS:
    .double +1.8
FIVE:
    .double +5  # These two could be combined into +0.5555556
NINTHS:         #   but that would be less precise
    .double +9  #   ... I guess
THIRTY_TWO:
    .double +32

.text
main:
    subl    $STACK_SPACE, %esp
    leal    tempASys(%esp), %eax
    movl    %eax, 8(%esp)
    leal    tempA(%esp), %eax
    movl    %eax, ptr1(%esp)
PromptForTemp:
    movl    $PROMPT_STRING, format(%esp)
    call    printf
    movl    $INPUT_STRING, format(%esp)
    call    scanf
    movl    tempASys(%esp), %eax
    andl    $UPPERCASE, %eax            # Force tempASys to uppercase
    movl    %eax, tempBSys(%esp)        # Copy tempASys to tempBSys
    cmpl    $F, %eax                    # If (tempASys == 'F')
    je      FtoC                        #   goto FtoC
    cmpl    $C, %eax                    # ElseIf (tempASys != 'C')
    jne     PromptForTemp               #   goto PromptForTemp
CtoF:
    movl    $F, tempASys(%esp)
    movsd   tempA(%esp), %xmm0          # Copy tempA to X
    movsd   %xmm0, tempB(%esp)          # Copy X to tempB
    mulsd   NINE_FIFTHS, %xmm0          # X *= 9/5
    addsd   THIRTY_TWO, %xmm0           # X += 32
    jmp     Finish
FtoC:
    movl    $C, tempASys(%esp)
    movsd   tempA(%esp), %xmm0          # Copy tempA to X
    movsd   %xmm0, tempB(%esp)          # Copy X to tempB
    subsd   THIRTY_TWO, %xmm0           # X -= 32
    mulsd   FIVE, %xmm0                 # X *= 5
    divsd   NINTHS, %xmm0               # X /= 9
Finish:
    movsd   %xmm0, tempA(%esp)          # Copy X to tempA
    movl    $FORMAT_STRING, (%esp)
    call    printf
    addl    $STACK_SPACE, %esp
    ret