From 05ff6d55f6d6b0c8691b737dea2bc160b04178e2 Mon Sep 17 00:00:00 2001 From: Jan Sucan Date: Sat, 11 Mar 2023 13:35:05 +0100 Subject: 3_b_3: Add solution --- ch03/3_b_3.hs | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) create mode 100644 ch03/3_b_3.hs (limited to 'ch03') diff --git a/ch03/3_b_3.hs b/ch03/3_b_3.hs new file mode 100644 index 0000000..c0d62d5 --- /dev/null +++ b/ch03/3_b_3.hs @@ -0,0 +1,24 @@ +-- Write a function that computes the mean of a list, i.e. the sum of all +-- elements in the list divided by its length. (You may need to use the +-- fromIntegral function to convert the length of the list from an integer into +-- a floating point number.) + +sumOfList [] = 0 +sumOfList (x:xs) = x + (sumOfList xs) + +meanOfList [] = 0 +meanOfList xs = sum / (fromIntegral len) + where sum = sumOfList xs + len = length xs + +-- ghci> :l 3_b_3.hs +-- [1 of 1] Compiling Main ( 3_b_3.hs, interpreted ) +-- Ok, one module loaded. +-- ghci> meanOfList [] +-- 0.0 +-- ghci> meanOfList [1] +-- 1.0 +-- ghci> meanOfList [1, 3] +-- 2.0 +-- ghci> meanOfList [2.3, 4.5, 6.9] +-- 4.566666666666666 -- cgit v1.2.3