tail-recursion

问题 Out of curiosity I was trying to generate a tail call opcode using C#. Fibinacci is an easy one, so my c# example looks like this: private static void Main(string[] args) { Console.WriteLine(Fib(int.MaxValue, 0)); } public static int Fib(int i, int acc) { if (i == 0) { return acc; } return Fib(i - 1, acc + i); } If I build it in release and run it without debugging I do not get a stack overflow. Debugging or running it without optimizations and I do get a stack overflow, implying that tail

问题 Out of curiosity I was trying to generate a tail call opcode using C#. Fibinacci is an easy one, so my c# example looks like this: private static void Main(string[] args) { Console.WriteLine(Fib(int.MaxValue, 0)); } public static int Fib(int i, int acc) { if (i == 0) { return acc; } return Fib(i - 1, acc + i); } If I build it in release and run it without debugging I do not get a stack overflow. Debugging or running it without optimizations and I do get a stack overflow, implying that tail

问题 Im trying do some work on Project Euler for fun, but I got stuck now on an problem and want to move on but cant seem to get my function working. Im trying to get count the primefactors of a given integer. The function works on smaller numbers such as 13195: > primeFactor 13195 [29,13,7,5] But when I run a bigger number such as 600851475143: > primeFactor 601851475143 [] This seems really weird to me. I know haskell is a lazy language, but I don´t think it should be that lazy... primeFactor' :

问题 Is there a way to define a function in Clojure that is automatically tail-call-optimized? e.g. (defrecur fact [x] (if (= x 1) 1 (* x (fact (dec x))))) would be translated internally to something like: (defn fact [x] (loop [n x f 1] (if (= n 1) f (recur (dec n) (* f n))))) Can you tell me if something like this already exists? 回答1: The short answer is "No". The slightly longer answer is that Clojure is deliberately designed to require explicit indication where Tail Call Optimisation is desired

问题 According to answers to that question: Which, if any, C++ compilers do tail-recursion optimization? it seems, that compiler should do tail-recursion optimization. But I've tried proposed options and it seems that compiler can't do this optimization in case of template functions. Could it be fixed somehow? 回答1: I don't use the MS compilers, but GCC can certainly do tail-recursion optimisation for templates. Given this function: template <typename T> T f( T t ) { cout << t << endl; if ( t == 0

问题 Closed . This question needs details or clarity. It is not currently accepting answers. Want to improve this question? Add details and clarify the problem by editing this post. Closed 5 years ago . Basically what I'm trying to do boils down to function a() { // Do stuff that waits for things etc b(a); } function b(f) { f() } function a() { b(a); }; function b(f) { f(); }; a() That will cause a too much recursion error after a while though. Apparently javascript doesn't support tail-recursion

问题 How to implement flatten list in prolog ,with tail recursion ? This is code for flatten/2 with simple recursion (that is mean without back-tracking): flatten([], []). flatten([L|Ls], FlatL) :- !, flatten(L, NewL), flatten(Ls, NewLs), append(NewL, NewLs, FlatL). flatten(L, [L]). ?- flatten([1, [2,3], [4]], X). X=[1,2,3,4]. I'm trying to do the same algorithm but with tail recursion (Accumulator). For exemple, the predicate sum/2 returns the addition of all member of the list, with backtracking

问题 I've stubled upon a function (here on SO) which writes a file, but makes sure to not overwrite a file: function writeFile(i){ var i = i || 0; var fileName = 'a_' + i + '.jpg'; fs.exists(fileName, function (exists) { if(exists){ writeFile(++i); } else { fs.writeFile(fileName); } }); } Now there is an interesting comment below which says: Minor tweak: Since JavaScript doesn't optimize tail recursion away, change writefile(++i) to process.nextTick(function(i) {writefile(++i);}); that will keep

问题 Consider the following numbers nested by vectors in a tree-structure (def tree [7 9 [7 5 3 [4 6 9] 9 3] 1 [2 7 9 9]]) My goal is to find the path to the first even number that can be found by traversing the tree: In the upper example this would be 4, the path from the root to this node would be [2 3 0] (def result [2 3 0]) I got some difficulties writing a function tho archive this. However, the following function finds the first even number, not its path: (defn find-even [x] (if (vector? x)

问题 I wrote a function to calculate the power of an integer then take modulus. I wonder if what I did is tail recursion : int takeModulusTAILRECURSION(int coef, int x, int n, int module){ int result = 0; if ( n > 0 ) result = takeModulusTAILRECURSION( mod(coef * x, module), x , n - 1, module ); else if ( n == 0) result = mod ( coef , module ); return result; } //take modul of an integer ( both negative and positive ) int mod(int x, int modul){ while ( x < 0) x += modul; return x % modul; } Here