variable problem (very big number)

[roelof]

Hello,

I try to make a exercise where I have to store a number which exist of 12 numbers in a variable. The number looks like this : 869144826000
But as far as I know a long int or a unsigned int can go to a number exist of 9 numbers.

How can I store this number in a variable ?
I know there are arrays but in this book but that is chapter 8 and I work now in chapter5.

I use this book : C Programming : A modern Approach 2nd Edition.

Roelof



Roelof

[ShashiKantSuman]

You can store this number using structure like

struct Number
{
	double base;
	int power;
};

Then you number is like a * 10^b.

[kuchiku]

You can store this number using structure like

struct Number
{
	double base;
	int power;
};

Then you number is like a * 10^b.

I am new in c programming. Could you please give an example code in using that struct?

how would you assign the value "869144826000" to that?

[kuchiku]

You can store this number using structure like

struct Number
{
	double base;
	int power;
};

Then you number is like a * 10^b.

I am new in c programming. Could you please give an example code in using that struct?

how would you assign the value "869144826000" to that?

[roelof]

Hoi,

Structs are not the solution.

Im also new in C programming and structs are even later discussed in the book then array's.

Roelof

[ShashiKantSuman]

This is a sample program for multiplication.

#include <stdio.h>
# include <stdlib.h>
typedef	struct Number
{
	float Base;
	int Power;
}NUMBER;
int main()
{
	NUMBER *num1,*num2,*num3;
	num1 = (NUMBER*)malloc(sizeof(NUMBER));
	num2 = (NUMBER*)malloc(sizeof(NUMBER));
	num3 = (NUMBER*)malloc(sizeof(NUMBER));
	printf("Enter two number in a * 10^b format\n\n");
	scanf("%f%d%f%d",&num1->Base,&num1->Power,&num2->Base,&num2->Power);
	num3->Base = num1->Base * num2->Base;
	num3->Power = num1->Power+num2->Power;
	printf("Result is: %f * 10^%d\n",num3->Base,num3->Power);
	getch();
	return 1;
}

how would you assign the value "869144826000" to that?

You can assign as 8.69144 * 10 ^11.

[CommonTater]

Why wouldn't you just use a long long int ?
(uint64_t if you have the stdint.h header)


They get up to 15 digits very nicely.

[roelof]

Hello,

I did not know that a long long int exist.
But it does the job.

Problem solved.

Roelof

[CommonTater]

You'r compiler's documentation should give you details on the types and their ranges...

What compiler are you using... (I've probably asked this before, but can't recall right now)

[roelof]

hello,

I use GCC on a Debain testing box.

Roelof

[CommonTater]

Ok... I'm not linux people so maybe one of the others can point you to the right place...

One thing you can try in the mean time is to open the stdint.h file in a text editor --don't make changes!-- and look at what's available there.

[anduril462]

I don't know of where to find a list of valid types supported by gcc, other than knowing that gcc supports most of C99, and thus should support valid C99 types, including long long. As for what's valid C99, if you have a really good, trustworthy book, they might mention all the integral types, or you can check out the standard: http://www.open-std.org/jtc1/sc22/wg...docs/n1362.pdf.

[CommonTater]

I don't know of where to find a list of valid types supported by gcc, other than knowing that gcc supports most of C99, and thus should support valid C99 types, including long long. As for what's valid C99, if you have a really good, trustworthy book, they might mention all the integral types, or you can check out the standard: http://www.open-std.org/jtc1/sc22/wg...docs/n1362.pdf.

WOW... that's awful ... it gives whole new meaning to the old saw about bugs... "Undocumented Features"...