# Add polynomials

### From HaskellWiki

(Difference between revisions)

(Numeric Prelude) |
m (Remove the incomplete multiply function) |
||

Line 26: | Line 26: | ||

addManyPolys :: [Poly] -> Poly | addManyPolys :: [Poly] -> Poly | ||

addManyPolys ps = foldl 0 addPoly ps | addManyPolys ps = foldl 0 addPoly ps | ||

− | |||

− | |||

− | |||

− | |||

− | |||

− | |||

− | |||

main = do | main = do |

## Latest revision as of 05:07, 3 May 2009

Polynomial Algebra

#!/usr/local/bin/runhugs module Main where type Poly = [(Int,Int)] -- assume sorted by increasing exponent. -- data Rational = (Poly, Poly) -- an interesting thing to observe: -- when adding, the null polynomial is zero. -- when multiplying it is one. This concept emerges implicitly -- in these definitions. addPoly :: Poly -> Poly -> Poly addPoly [] ys = ys addPoly xs [] = xs addPoly ((a,b):xs) ((c,d):ys) | a == c = ((a,b+d):(addPoly xs ys)) | a < c = ((a,b):(addPoly xs ((c,d):ys))) | a > c = ((c,d):(addPoly ((a,b):xs) ys)) addManyPolys :: [Poly] -> Poly addManyPolys ps = foldl 0 addPoly ps main = do putStr $ show $ addPoly [(0,1),(2,1)] [(0,1)]

## [edit] See also

- Numeric Prelude [1]
- HTam [2]