Thread: Constant too big error

I am trying to put a large number inside an int variable but I am having problems. The compiler I am using is microsofts visual C++ compiler v6.0.

I get this error.

error C2177: constant too big

I thought that directly declaring it as an int wouldn't work because only 4 bytes is allocated to an int so I tried using new to allocate enough space.

Code:

int* number = new int [8];
number = 39990881947540732160326;

It still says constant too big.

I tried declaring the number as type char* then using atoi and atol to convert it into a large integer but that didn't work using the code below.

Code:

	char* number = "39990881947540732160326";
	int number2 = atol(number);
	cout<<number2;

Then I tried declaring it as a type char* again, creating an integer with new large enough to hold the correct number of bytes and then using a for loop, to move each number for the char pointer into the large int array. Like below.

Code:

	char* number = "39990881947540732160326";
	int* number2 = new int [strlen(number)];
	for(int i = 0; i < strlen(number); i++){
		number2[i] = number[i];
	}
	cout<<number2;

This still doesn't work

I realise I over allocate space in the example above, it should be

Code:

 strlen(number) / 4

shouldn't it?

But if I did that wouldn't it mean there are not enough elements of the array for me to store each number in? Like if I do it the first way isn't there enough elements but each element can hold 4 numbers right? Or should I do a nested loop inside the other loop, moving 4 numbers into one element of the array somehow, so that I can create a proper sized integer pointer so that there is not extra space allocated.

Anyway, I can worry about proper space allocation later , if anybody can help it is appreciated.

I see.

So as that is the maximum size for an int on my processor aswell, I will need to use another data type right?

Yes, you'll need another data type.

If you're just after an answer, then look up GMP
http://www.swox.com/gmp/

Originally Posted by Blackroot

You can try a long int:

Code:

long number2;

But I dont think a long can get that big either.

LONG_MAX gives the same as INT_MAX.

Originally Posted by Salem

Yes, you'll need another data type.

If you're just after an answer, then look up GMP
http://www.swox.com/gmp/

I will look into it thanks.