I have been trying to simulate "Russian peasant multiplication" in
Haskell , but I can't produce a list of tuples after I enter 2 integers.
I have tried constructing many accumulator functions to do so, but keep
getting IO errors. This is NOT a homework question. I am a senior
learning Haskell, and finding it very enjoyable, although frustrating at
times.
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main1 = do
putStrLn "Russian Peasant Multiplication \n"
putStrLn "Enter 2 integers : "
a <- getInt
b <- getInt
-- at this point I would like a list of tuples of the form [ (a
`div` 2 , b*2 )] , starting with the 2 initial integers, down to
-- where the first value is 1 in the last tuple: ie if the
initial numbers were 121 and 3 say , I'd like the list
-- [ (121,3) , (60,6) , (30,12) , (15,24) , (7,48) , (3,96) ,
(1,192) ] produced and available in main for further manipulation.
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-- to read in an Int , I used :
getInt :: IO Int
getInt = do line <- getLine
return( read line :: Int)
