View Problem
Perform an action multiple times based on a boolean condition, checked before the first action (WHILE .. DO)
Starting with a variable x=1, Print the sequence 
ruby
cpp C++/CLI .NET 2.0
cpp
fsharp
fsharp
erlang
erlang
csharp
haskell
haskell
Submit a new solution for ruby, cpp, fsharp, erlang ...
There are 10 other solutions in additional languages (clojure, fantom, groovy, java ...)
"1,2,4,8,16,32,64,128," by doubling x and checking that x is less than 150.
x=1
while x < 150
puts x
x <<= 1
end
while x < 150
puts x
x <<= 1
end
int x = 1;
while (x < 150) { x *= 2; Console::Write("{0},", x); }
Console::WriteLine();
while (x < 150) { x *= 2; Console::Write("{0},", x); }
Console::WriteLine();
for (int x = 1; x < 150; x *= 2) { std::cout << x << ","; }
std::cout << std::endl;
std::cout << std::endl;
let mutable x = 1
while x < 150 do printf "%d, " x ; (x <- x * 2) done
while x < 150 do printf "%d, " x ; (x <- x * 2) done
// The problem is clearly geared towards imperative languages ;-)
// No need to mutate any variable, here's how to do it loop-free functional:
let rec powers2 i = seq { if i < 150 then yield i; yield! powers2 (i*2) }
powers2 1 |> Seq.iter (fun i -> printf "%i, " i)
// No need to mutate any variable, here's how to do it loop-free functional:
let rec powers2 i = seq { if i < 150 then yield i; yield! powers2 (i*2) }
powers2 1 |> Seq.iter (fun i -> printf "%i, " i)
X = 1, print_while_X_less_150(X).
Pred = fun (X) -> X < 150 end,
Action = fun (X) -> io:format("~B,", [X]), X * 2 end,
X = 1,
while_do(Pred, Action, X).
Action = fun (X) -> io:format("~B,", [X]), X * 2 end,
X = 1,
while_do(Pred, Action, X).
int x = 1;
while (x < 150)
{
x *= 2;
Console.Write("{0},", x);
}
while (x < 150)
{
x *= 2;
Console.Write("{0},", x);
}
main :: IO ()
main = loop 1
where
loop x | x < 150 = do
putStr (show x ++ ",")
loop (x * 2)
loop _ = return ()
main = loop 1
where
loop x | x < 150 = do
putStr (show x ++ ",")
loop (x * 2)
loop _ = return ()
main = mapM_ print $ takeWhile (<150) $ iterate (* 2) 1
Submit a new solution for ruby, cpp, fsharp, erlang ...
There are 10 other solutions in additional languages (clojure, fantom, groovy, java ...)
