Kochan Solution Exercise 6-6

/* SOLUTION: ---------------
 "Programming in Objective C"
 Kochan, p130, Exercise 6-6.

 "Write a program that takes an integer keyed in from the terminal and extracts and displays each digit of the integer in English. So if the user types in 932, the program should display the following:
 nine
 three
 two"

 */


/*

 I've seen a number of solutions for this online but I didn't like any of them as they
 either:
 i. included C library functions
 or
 ii. used concepts that Kochan hasn't introduced yet

 The solution below, while far from elegant, relies only on things you've seen in the book
 up to this point and makes proper use of Objective C structures.

 Hope it helps!

 Phil
 applehelpwriter.com 2013

 */


#import <Foundation/Foundation.h>

/*---------------------------------*/
// ~/objcAgain1.xcodeproj

@interface NumToWord : NSObject {

    long inputnumber;
}

-(void) setInputNumber: (long) value;
-(void) printNum;
@end

/*---------------------------------*/



@implementation NumToWord
-(void) setInputNumber:(long)value {
    inputnumber = value;
}

-(void) printNum {


    int numword[10];
    int rem = 0;
    int iterator = 0;
    int i = 9; //to reverse: set i to the last element of the array and count down



    while (inputnumber > 0){

        //dealing with any zero's:
        while ((inputnumber % 10) == 0){
            numword[i] = 0;
            iterator++;
            --i; //counting backwards so the values are stored in reverse
            inputnumber /= 10;

        }//end while

        //dealing with all non-zero numbers
        rem = (inputnumber % 10);

        //setting the numbers to the end of the array and counting down
        for (i = i; ((numword[i] = rem) ); --i){
            ++iterator;
            inputnumber /= 10;

            rem = (inputnumber % 10);
        }//end for

    }//end while


    // start printing from the first used value in the array to the last
    //that's why we needed the iterator, to find the first used valiue in the array
    for (i = (10-iterator); i < 10; ++i)
        switch (numword[i]) {
            case 0:
                NSLog(@"zero ");
                break;
            case 1:
                NSLog(@"one ");
                break;
            case 2:
                NSLog(@"two ");
                break;
            case 3:
                NSLog(@"three ");
                break;
            case 4:
                NSLog(@"four ");
                break;
            case 5:
                NSLog(@"five ");
                break;
            case 6:
                NSLog(@"six ");
                break;
            case 7:
                NSLog(@"seven ");
                break;
            case 8:
                NSLog(@"eight ");
                break;
            case 9:
                NSLog(@"nine ");
                break;
            default:
                NSLog(@"my error");
                break;
        }//end switch



}

@end

/*---------------------------------*/



int main(int argc, const char * argv[])
{
    long number;
    int counter = 0;
    int i = 0;

    @autoreleasepool {
        NumToWord *myNumToWord = [[NumToWord alloc] init];

        NSLog(@"Type a number: \n");
        scanf("%ld", &number);

        //if the user only enters '0' print 'zero'
        if (number == 0)
            NSLog(@"zero");

        //otherwise, determine the number of digits, up to 10, i.e. max num 9999999999;

        else if (number < 10)
            counter = 1;
        else if (number < 100)
            counter = 2;
        else if (number < 1000)
            counter = 3;
        else if (number < 10000)
            counter = 4;
        else if (number < 100000)
            counter = 5;
        else if (number < 1000000)
            counter = 6;
        else if (number < 10000000)
            counter = 7;
        else if (number < 100000000)
            counter = 8;
        else if (number < 1000000000)
            counter = 9;
        else if (number < 10000000000)
            counter = 10;
        else
            NSLog(@"Number out of range");


        [myNumToWord setInputNumber: number];
        for (i=0; i < counter; ++i)
            [myNumToWord printNum];

    }//end autoreleasepool

    return 0;
}//end main