C++: atoi problem when character array has 11 or more entries

[Redrum]

what jehanum said

cin the character string char by char, run atoi char by char, then output the integer into an array of ints, int by int

this will let convert huge strings of chars to massive numbers

[DreamWarrior]

Originally Posted by Redrum

what jehanum said

cin the character string char by char, run atoi char by char, then output the integer into an array of ints, int by int

this will let convert huge strings of chars to massive numbers

Why the fuck would you do that? Sure, an array of useless numbers that you'll have to design your own addition and multiplication logic on.... For that matter, one that is a large fucking waste of space! You need 4 bits to represent 10 decimal digits, you're going to stuff them in 32 bit ints in an array? GENIUS! Even using a char array is a fucking waste of 4 bits per.... No real bigint library would be implemented like that.

If uint64_t is available, use that. If that is not enough bits, pull down a bigint library, there are a few that were submitted for inclusion in Boost but didn't make it.

Edit: and Graze, dude, not to be a dick, but if you are too ignorant to figure out that you are overflowing an integer, you certainly are not smart enough to properly reinvent this wheel.

[Grazehell]

Originally Posted by DreamWarrior

Why the fuck would you do that? Sure, an array of useless numbers that you'll have to design your own addition and multiplication logic on.... For that matter, one that is a large fucking waste of space! You need 4 bits to represent 10 decimal digits, you're going to stuff them in 32 bit ints in an array? GENIUS! Even using a char array is a fucking waste of 4 bits per.... No real bigint library would be implemented like that.

If uint64_t is available, use that. If that is not enough bits, pull down a bigint library, there are a few that were submitted for inclusion in Boost but didn't make it.

Edit: and Graze, dude, not to be a dick, but if you are too ignorant to figure out that you are overflowing an integer, you certainly are not smart enough to properly reinvent this wheel.

This entire exercise is me learning C++. Don't get on your high horse about it. There were other ways I could have gone about this that would have actually worked but would not have taken me down the path of strol or stroll. Something my 1000 page C++ book never mentions and only mentions atoi eight time.
My idea isn't necessarily to successfully reinvent the wheel but what I learn trying.

[Jehannum]

Originally Posted by DreamWarrior

Why the fuck would you do that? Sure, an array of useless numbers that you'll have to design your own addition and multiplication logic on.... For that matter, one that is a large fucking waste of space! You need 4 bits to represent 10 decimal digits, you're going to stuff them in 32 bit ints in an array? GENIUS! Even using a char array is a fucking waste of 4 bits per.... No real bigint library would be implemented like that.

If uint64_t is available, use that. If that is not enough bits, pull down a bigint library, there are a few that were submitted for inclusion in Boost but didn't make it.

Edit: and Graze, dude, not to be a dick, but if you are too ignorant to figure out that you are overflowing an integer, you certainly are not smart enough to properly reinvent this wheel.

Yeah, but a uint64_t is only going to support a number 19 digits long, and apparently this guy's got really long strings of binary. a char array is really the way to go here, assuming a large integer class isn't in the offering.

[DreamWarrior]

Originally Posted by Jehannum

Yeah, but a uint64_t is only going to support a number 19 digits long, and apparently this guy's got really long strings of binary. a char array is really the way to go here, assuming a large integer class isn't in the offering.

A char array is not the way to go if you have to do math. If you don't have to do math, then some would argue to always use string (though I don't advocate that sort of useless waste, lol.)

[Great Tiger]

my brain hurts in here.

[:ninja:]

1000 page C++ books and character arrays to do string binary to integer conversion?

Last time I leave my embedded C cave. You guys are nuts.

[Jehannum]

Originally Posted by DreamWarrior

A char array is not the way to go if you have to do math. If you don't have to do math, then some would argue to always use string (though I don't advocate that sort of useless waste, lol.)

I'm pretty sure whatever he's doing is in that category anyhow (useless waste).

[aoeoae]

Originally Posted by :ninja:

1000 page C++ books and character arrays to do string binary to integer conversion?

Last time I leave my embedded C cave. You guys are nuts.

i wonder if he's using deitel. i felt like i was wasting my time with C++ until i switched to much more concise book (accelerated C++, koenig & moo). then i switched to a more concise language, python

[Grazehell]

Originally Posted by aoeoae

i wonder if he's using deitel. i felt like i was wasting my time with C++ until i switched to much more concise book (accelerated C++, koenig & moo). then i switched to a more concise language, python

The book is fine. But you really can't expect me to learn everything from reading a book?

Seems like people a bit confused as to what the program was suppose to do. It was suppose to take in a wall of binary numbers and process them, not just them convert to decimal

[:ninja:]

Originally Posted by aoeoae

i wonder if he's using deitel. i felt like i was wasting my time with C++ until i switched to much more concise book (accelerated C++, koenig & moo). then i switched to a more concise language, python

Mmm... Python. Isn't that the language where you take 100 programmers and give them a problem to solve, and all 100 programs are identical?

[:ninja:]

Originally Posted by Grazehell

The book is fine. But you really can't expect me to learn everything from reading a book?

No, you're doing it right. You need to write programs and solve problems to get better at writing programs and solving problems. Not using strtoul with base 2 to convert strings of binary is a good exercise. An even better exercise, however, would be to write your own strtoul. Check out the source code from any free strtoul implementation and understand how it works. This is why developing for Linux and BSD is so useful... you're not using some hidden and poorly-documented API which is subject to change between releases.

I would argue that C++ is a silly language and is difficult to learn as an introduction to programming. The language provides so many "features" and some C++ developers get the idea that they need to use all of them in every program they write. Even worse, you get companies that only use a subset of C++ features, for the same reason.

With the things you are trying to learn right now, I would suggest you pick up K&R C. It is short, concise, and infinitely useful. Trying to toss in all the silly features of C++ and OOP when you're just trying to learn the basics is counterintuitive.


Also, operator overloading is the fucking devil.

[Jehannum]

Originally Posted by :ninja:

No, you're doing it right. You need to write programs and solve problems to get better at writing programs and solving problems. Not using strtoul with base 2 to convert strings of binary is a good exercise. An even better exercise, however, would be to write your own strtoul. Check out the source code from any free strtoul implementation and understand how it works. This is why developing for Linux and BSD is so useful... you're not using some hidden and poorly-documented API which is subject to change between releases.

I would argue that C++ is a silly language and is difficult to learn as an introduction to programming. The language provides so many "features" and some C++ developers get the idea that they need to use all of them in every program they write. Even worse, you get companies that only use a subset of C++ features, for the same reason.

With the things you are trying to learn right now, I would suggest you pick up K&R C. It is short, concise, and infinitely useful. Trying to toss in all the silly features of C++ and OOP when you're just trying to learn the basics is counterintuitive.


Also, operator overloading is the fucking devil.

I occasionally reference that book to this day ('course, I work in C, not C++). I've had it since 1996, I think.

Ad hoc polymorphism is proper OOP design, IMO. Of course, badly done overloading takes away from it.