how to solve problem"Huge Integer Class"?

[khajeddin]

the problem is:
Create a class HugeInteger which use 40-element array of digits to store integers as larg as 40 digits each.Provide methods input, output, add, subtract
how to add to arrays ?

[r035198x]

the problem is:
Create a class HugeInteger which use 40-element array of digits to store integers as larg as 40 digits each.Provide methods input, output, add, subtract
how to add to arrays ?

And what have done so far?

[khajeddin]

well i thought i can add each digit(character ) of the string1 and string2 with eachother and put it in the same position of the third string as shown below:

int[] a1=new int[40];
int[] a2=new int[40];
int[] a3=new int[40]; 
.....
a3[0]=a1[0]+a2[0];
 

and ofcourse have some rule too do this correctly in the program...and do the same thing for subtract...
but my professor didn't accept this algorithm,he said we should get two string of 40-digit number and add or subtract them without convert each digit (each character) into integer and do the same thing as i showd above!
well i do'nt know what to do so?!!!

[r035198x]

the problem is:
Create a class HugeInteger which use 40-element array of digits to store integers as larg as 40 digits each.Provide methods input, output, add, subtract
how to add to arrays ?

What type is the 40-element array?

[JosAH]

well i thought i can add each digit(character ) of the string1 and string2 with eachother and put it in the same position of the third string as shown below:

int[] a1=new int[40];
int[] a2=new int[40];
int[] a3=new int[40]; 
.....
a3[0]=a1[0]+a2[0];
 

and ofcourse have some rule too do this correctly in the program...and do the same thing for subtract...
but my professor didn't accept this algorithm,he said we should get two string of 40-digit number and add or subtract them without convert each digit (each character) into integer and do the same thing as i showd above!
well i do'nt know what to do so?!!!

Please don't write in ambiguous terms. Does your assignment say that you
have to use a fourty element char array or do you have to use Strings?

If you decide to use the char type for every single digit you do need a bit of
conversion because the numerical value of a digit char is not equal to the digit
itself.

kind regards,

Jos

[khajeddin]

let me describe from the begining as my professor want:
i have to get two array of 40-digit number(num1 & num2),then convert these two into strings of 40-digit number( array---->string) and then do add and subtract on these two strings.
( NOTE: what not to do : i shouldn't convert every digit(character in strings) into integer and i have do some kind of character add or character subtract on them).
and i have no sugesstion how to do this.please tell some about this!

[JosAH]

let me describe from the begining as my professor want:
i have to get two array of 40-digit number(num1 & num2),then convert these two into strings of 40-digit number( array---->string) and then do add and subtract on these two strings.
( NOTE: what not to do : i shouldn't convert every digit(character in strings) into integer and i have do some kind of character add or character subtract on them).
and i have no sugesstion how to do this.please tell some about this!

So your professor doesn't want you to convert that String to an int; it can't be
done anyways because a fourty digit number is way too large for an int. You're
not allowed to convert it to a BigInteger either (my guess) and you have to add
those 40 digit numbers yourself. Well here goes:

If you have to add two characters (representing a single decimal digit) plus a
carry value (also representing a single decimal digit), you have to do this:

char a; 
char b;
char c; // the carry value
char result= (char)(a+b+c-('0'+'0'));
if (result > '9') { 
   // determine new carry and adjust result
}
else
   c= '0'; // no carry

If your professor doesn't like this, tell him/her to give me a call ;-)

kind regards,

Jos

[khajeddin]

please let me tell you what i understand from this way:
we know that to convert every character to an integer we have to subtract 48 from that character and because charachter 0 is equal to -48 you do that to convert a & b into integers!!!!
thank you very much
iwill write code of this program right away and send this to know your what you think about that...:)

[JosAH]

please let me tell you what i understand from this way:
we know that to convert every character to an integer we have to subtract 48 from that character and because charachter 0 is equal to -48 you do that to convert a & b into integers!!!!
thank you very much
iwill write code of this program right away and send this to know your what you think about that...:)

Yep, you got it. Best of luck with writing your program code.

kind regards,

Jos

[eng200]

Yep, you got it. Best of luck with writing your program code.

kind regards,

Jos

hey josah!
i didn't understand wat u meant by the "carry" thing,i mean i understand what it means it's just that i dnt know where to put it in my code i dnt even know where to start from,,,,our professor gave us this question as a bonus so would u please write the whole code>? if ur free,no obligations but i would be very grateful if u sent it ;)


thanks