From 7d375e7c856ef4f6235e9096edd13e871f2229e6 Mon Sep 17 00:00:00 2001
From: Neil Smith <neil.git@njae.me.uk>
Date: Mon, 16 Dec 2019 15:43:10 +0000
Subject: [PATCH] Day 14 done.

---
 advent14/src/advent14.hs | 45 ++++++++++++++++++++++------------------
 1 file changed, 25 insertions(+), 20 deletions(-)

diff --git a/advent14/src/advent14.hs b/advent14/src/advent14.hs
index c8a1456..1fafe9b 100644
--- a/advent14/src/advent14.hs
+++ b/advent14/src/advent14.hs
@@ -10,8 +10,6 @@ import Text.Megaparsec.Char
 import qualified Text.Megaparsec.Char.Lexer as L
 import qualified Control.Applicative as CA
 
-
-import Data.Ratio
 import Data.List
 import qualified Data.Map.Strict as M
 import Data.Map.Strict ((!))
@@ -28,45 +26,51 @@ type Requirement = M.Map String Int
 main :: IO ()
 main = do 
         text <- TIO.readFile "data/advent14.txt"
-        let rules = successfulParse text
-        let ruleBase = mkRuleBase rules
+        -- let rules = successfulParse text
+        -- let ruleBase = mkRuleBase rules
+        let ruleBase = successfulParse text
         -- print rules 
         -- print ruleBase
         print $ part1 ruleBase
         print $ part2 ruleBase
 
+oreLimit :: Int
 oreLimit = 10^12
 
+mkRuleBase :: [Rule] -> RuleBase
 mkRuleBase = foldl' addRule M.empty
     where addRule base rule = M.insert (_chemical $ _rhs rule) rule base
 
+
 -- part1 rules = required!"ORE"
 --     where required0 = M.singleton "FUEL" 1
---           required = produce rules required0
+--           required = produce rules required
 part1 rules = oreForFuel rules 1
 
-part2 rules = searchFuel rules 1 upper 
+part2 rules = searchFuel rules (upper `div` 2) upper 
     where upper = findUpper rules (oreLimit `div` base)
           base = oreForFuel rules 1
 
-
+oreForFuel :: RuleBase -> Int -> Int
 oreForFuel rules n = required!"ORE"
     where required0 = M.singleton "FUEL" n
           required = produce rules required0 
 
-findUpper _ n | trace ("Upper " ++ show n) False = undefined
+findUpper :: RuleBase -> Int -> Int
+-- findUpper _ n | trace ("Upper " ++ show n) False = undefined
 findUpper rules n = if ore > oreLimit
                     then n
                     else findUpper rules (n * 2)
     where ore = oreForFuel rules n 
 
-searchFuel _ lower upper | trace ("Search " ++ show lower ++ " - " ++ show upper) False = undefined
+searchFuel :: RuleBase -> Int -> Int -> Int
+-- searchFuel _ lower upper | trace ("Search " ++ show lower ++ " - " ++ show upper) False = undefined
 searchFuel rules lower upper 
     | upper == lower = upper
     | otherwise = if ore > oreLimit
-                  then searchFuel rules lower mid
+                  then searchFuel rules lower (mid - 1)
                   else searchFuel rules mid upper
-    where mid = (upper + lower) `div` 2
+    where mid = (upper + lower + 1) `div` 2
           ore = oreForFuel rules mid
 
 
@@ -77,20 +81,22 @@ produce rules required
     where outstanding =  M.filter (> 0) $ nonOre required
           (chem, qty) = M.findMin outstanding
           rule = rules!chem
-          qty' = qty - (_quantity $ _rhs rule)
+          productQty = _quantity $ _rhs rule
+          applications = max 1 (qty `div` productQty)
+          qty' = qty - (applications * productQty)
           required' = M.insert chem qty' required
-          required'' = S.foldl addRequrirement required' (_lhs rule)
+          required'' = S.foldl (addRequrirement applications) required' (_lhs rule) 
 
 
 nonOre :: Requirement -> Requirement
 nonOre = M.filterWithKey (\c _ -> c /= "ORE")
 
 
-addRequrirement :: Requirement -> Reagent -> Requirement
-addRequrirement requirements reagent = M.insert chem qty' requirements
+addRequrirement :: Int -> Requirement -> Reagent -> Requirement
+addRequrirement n requirements reagent = M.insert chem qty' requirements
     where chem = _chemical reagent
           qty = M.findWithDefault 0 chem requirements
-          qty' = qty + (_quantity reagent) 
+          qty' = qty + (n * _quantity reagent) 
 
 
 -- Parse the input file
@@ -108,8 +114,7 @@ arrowP = symb "=>"
 commaP = symb ","
 identifierP = some alphaNumChar <* sc
 
-
-rulesP = many ruleP
+rulesP = mkRuleBase <$> many ruleP
 
 ruleP = Rule <$> reagentsP <* arrowP <*> reagentP
 
@@ -117,8 +122,8 @@ reagentP = Reagent <$> integer <*> identifierP
 reagentsP = S.fromList <$> reagentP `sepBy` commaP
 
 -- successfulParse :: Text -> [Vec]
-successfulParse :: Text -> [Rule]
+successfulParse :: Text -> RuleBase
 successfulParse input = 
         case parse rulesP "input" input of
-                Left  _err -> [] -- TIO.putStr $ T.pack $ parseErrorPretty err
+                Left  _err -> M.empty -- TIO.putStr $ T.pack $ parseErrorPretty err
                 Right rules -> rules
-- 
2.34.1