fibonacci

I'm just starting to learn F# using VS2010 and below is my first attempt at generating the Fibonacci series. What I'm trying to do is to build a list of all numbers less than 400. let fabList = let l = [1;2;] let mutable a = 1 let mutable b = 2 while l.Tail < 400 do let c = a + b l.Add(c) let a = b let b = c My first problem is that on the last statement, I'm getting an error message "Incomplete structured construct at or before this point in expression" on the last line. I don't understand what I'm doing wrong here. While this seems to be an obvious way to build the list in a fairly efficient

Can that be done with no while loops? static void Main(string[] args) { Console.WriteLine("Please enter a number"); int number = Convert.ToInt32(Console.ReadLine()); Console.WriteLine(" #" + Fibonacci(number)); } public static int Fibonacci(int number) { if (number <= 1) { return 1; } else { return Fibonacci(number - 2) + Fibonacci(number - 1); } } I can't even add a Console.WriteLine in the body of base case since it gets executed [number] number of times; Not sure how to do this without loops... static void Main(string[] args) { Console.WriteLine("Please enter a number"); int number =

I am trying to make a program to find the nth Fibonacci number for 1 < n < 10^19. Here is my code using dynamic programming. memo = {} def fib(n): if n in memo: return memo[n] if n <= 2: f = 1 else: f = fib(n-1) + fib(n-2) memo[n]=f return f print fib(input()) % 1000000007 My code does not seem to work for large numbers. I get invalid response error. Any suggestions? Getting the Nth fibonacci number when N is 10^19 is not goign to work if you do it the naive way (at least i would guess it won't work). There's a much better way to do it. And this technique works with lots of series' like this.

How do I implement a recursive Fibonacci function with no loops running in O(n)? Typically I'd be against posting an answer to a homework question like this, but everything posted so far seems to be overcomplicating things. As said in the comments above, you should just use recursion to solve the problem like you would do iteratively. Here's the iterative solution: def fib(n): a, b = 0, 1 while n > 0: a, b = b, a+b n -= 1 return a Here's an equivalent recursive solution: def fib(n): def fib_help(a, b, n): return fib_help(b, a+b, n-1) if n > 0 else a return fib_help(0, 1, n) Note that in both

Generate the Fibonacci sequence in the fewest amount of characters possible. Any language is OK, except for one that you define with one operator, f , which prints the Fibonacci numbers. Starting point: 25 14 characters in Haskell : f=0:1:zipWith(+)f(tail f) f=0:scanl(+)1f Callum Rogers RePeNt, 9 , 8 chars 1↓[2?+1] Or 10 chars with printing: 1↓[2?+↓£1] Run using: RePeNt "1↓[2?+1]" RePeNt is a stack based toy language I wrote (and am still improving) in which all operators/functions/blocks/loops use Reverse Polish Notation (RPN). Command Explanation Stack ------- ----------- ----- 1 Push a 1