fibonacci | simplistic read-friendly blog template | Blog library

It gives out a "false" because Prolog is unsure whether there are more solutions after the first one it provides:

There is no way to "avoid or get around this error".

This is fundamental to C++: template parameters must be compile time constant expressions. That means that the values (or types) of template parameters must be fully defined at compile time.

An ordinary variable is something whose value is determined at run time. Therefore ordinary variables cannot be used as template parameters.

The only exception to this are special kind of variables called constexpr variables, which are variables that have defined constant values that are fully determined at compile time, too. As such, constexpr variables can be used as template parameters because they meet the requirements of a compile time constant expression.

But if you want to generate a Fibonacci sequence specified by a non-constexpr variable you just have to write an ordinary function that does that.

The Integer.MAX_VALUE is 2147483647.

Your maximum value expected is 2971215073, which is higher than this.

If you need to get higher numbers, use long like this:

Your problem is that you are computing the number of sums for n AND you are adding it to the sums of n+1 and n+2 which make you count them more than once.

Just count the number of sums for n without passing them down. Try this for example:

Javascript numbers are by default stored as floats, which means they're stored in scientific notation in memory (unless you're using BigInt), and they can only hold a limited amount of precision. So, a large number is represented somewhat like this: 1.2345 * 10^12, and there's a limit to the number of digits after the . that is stored in memory. You're dealing with some really large numbers, and are overflowing the amount of precision a single floating-point number can hold, which is why your computations end up wrong. BigInt is the solution to this, as it does not store numbers in scientific notation, and can hold an arbitrary amount of digits. However, you have to use BigInt all the way through your calculation - you can't just convert the scientific notation number to a BigInt at the end and expect the extra precision to pop out of nowhere.

So, to make it work properly, ensure you pass a BigInt into your fib function as a parameter (or convert it to one after it's passed in), and make sure each numeric literal is a BigInt literal (e.g. use 2n instead of 2). There is one caveat - a BigInt has to be an integer, it can not hold decimal values. This may require some adjustments to your algorithm.

If you want to learn more about the specific details of floats, and how much precision they can hold, take a look at this Wikipedia article.

All instructions operating on register lists always push, pop, load, store, ... the registers in ascending order of their numbers. So even if you write {R4, R2, LR}, what is actually pushed is {R2, R4, LR}. If you want a different order, you need separate PUSH instructions.

You cannot, the maximum value for int is 2,147,483,647 (32 bits of value). If you need big numbers you must use the appropriate variable type.

If for some reason you want to avoid BigInteger at all and your are not going to do any arithmetic operation later, you can always return a String

About the hackerrank problem, just modify the result variable type to BigInteger. Actually, they seem to be aware of the 32/64 bits issue... they are using a String value to prevent it.

There's no reason to keep the whole code-template structure. They just care about input/output. You are allowed to modify EVERYTHING but those two things.

This is their input:

This is their output (here you can see their output is expected to be a String):

The max value of Long is really the maximum of the type. Any calculation above this is giving you... well results you apparently do not expect. A check of the kind prev+next>Long.MAX_VALUE is a nonsense. It will never be truthy.

A bit of change that should make your program work is: prev > Long.MAX_VALUE - next

If you want to understand in greater detail, you can use the comparison as I wrote it and debug, placing a breakpoint inside the if block. Try to see the value of prev+next. See how it goes negative. This is because you have reached values outside what long can store.