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  1. Prepare
  2. Functional Programming
  3. Recursion
  4. Pascal's Triangle
  5. Discussions

Pascal's Triangle

  • strawstack
     + 1 comment

    I'm trying to explain to Haskell that a triangle is not a stright line. Can anyone help? (The output of the following code is 1 1 1 1 2 1 1 3 3 1 (without any new lines))

    -- FORMAT    
mat v = putStr ( (show v) ++ " " ) -- print value with space     

-- print tri value at coords
pas m n
    | n == 0 = 1 
    | m == n = 1
    | otherwise = pas (m-1) (n-1) + pas (m-1) n
      
-- print row of triangle 
row m = mapM_ (mat . (pas m) $) [0..m]   
    
-- print triangle until row
tri m = mapM_ (row) [0..(m-1)] 
    
main = do   
   m <- readLn :: IO Int
   tri m -- print tri to row m