day_04/solution_04a.nim

@@ -4,35 +4,19 @@ var result = 0
 var fn = if paramCount() > 0: paramStr(1) else: "input_04.txt"
 var lines = readFile(fn).strip.splitLines
 
-# ASSUMPTION: lottery numbers are < 128
-type
-    Card = ref object
-        play, pot: set[int8]
-var cards: seq[Card]
-
-proc points(card: Card): int =
-    let matches = (card.play * card.pot).len
-    if matches == 1:
-        result = 1
-    elif matches > 1:
-        result = 2 ^ (matches - 1)
-    else:
-        result = 0
-
-
 for line in lines:
-    var cardno: int
+    var card: int
     let cardspec = line.split(":", 1)
+    if scanf(cardspec[0].strip, "Card$s$i", card):
+        let play = cardspec[1].split("|")[0].strip.splitWhitespace().mapIt(it.strip).mapIt(it.parseInt).mapIt(it.int8).toSet
+        let jackpot = cardspec[1].split("|")[1].strip.splitWhitespace().mapIt(it.strip).mapIt(it.parseInt).mapIt(it.int8).toSet
+        #echo &"Card {card}: {left}, {right} => {left * right}"
+        let wins = (play * jackpot).len
+        if wins == 1:
+            result += 1
+        elif wins > 1:
+            result += 2 ^ (wins - 1)
 
-    if scanf(cardspec[0].strip, "Card$s$i", cardno):
-        let card = new Card
-        card.play = cardspec[1].split("|")[0].strip.splitWhitespace().mapIt(it.strip).mapIt(it.parseInt).mapIt(it.int8).toSet
-        card.pot = cardspec[1].split("|")[1].strip.splitWhitespace().mapIt(it.strip).mapIt(it.parseInt).mapIt(it.int8).toSet
-        echo &"Card {cardno}: {card.play}, {card.pot} => {card.points}"
-        cards.add(card)
-        result += card.points
-
-echo &"Cards processed: {cards.len}"
 echo &"Result: {result}"
 
 case fn:

day_04/solution_04b.nim

@@ -1,51 +0,0 @@
-import std/[cmdline, sequtils, setutils, strformat, strscans, strutils]
-
-var result = 0
-var fn = if paramCount() > 0: paramStr(1) else: "input_04.txt"
-var lines = readFile(fn).strip.splitLines
-
-# ASSUMPTION: lottery numbers are < 128
-type
-    Card = ref object
-        idx: int
-        play, pot: set[int8]
-var cards: seq[Card]
-
-proc value(card: Card): int =
-    (card.play * card.pot).len
-
-#proc `$`(card: Card): string =
-#    return &"Card idx={card.idx}: value={card.value}"
-
-
-for i, line in lines:
-    var cardno: int
-    let cardspec = line.split(":", 1)
-
-    if scanf(cardspec[0].strip, "Card$s$i", cardno):
-        let card = new Card
-        card.idx = i
-        card.play = cardspec[1].split("|")[0].strip.splitWhitespace().mapIt(it.strip).mapIt(it.parseInt).mapIt(it.int8).toSet
-        card.pot = cardspec[1].split("|")[1].strip.splitWhitespace().mapIt(it.strip).mapIt(it.parseInt).mapIt(it.int8).toSet
-        #echo &"Card {card.idx}: {card.play}, {card.pot} => {card.value}"
-        cards.add(card)
-
-var stack = cards
-while stack.len > 0:
-    result += len(stack)
-    var extra_cards: seq[Card]
-
-    for card in stack:
-        if card.value > 0:
-            extra_cards.add(cards[card.idx + 1..min(card.idx + card.value, cards.len - 1)])
-
-    stack = extra_cards
-
-#echo &"Cards processed: {cards.len}"
-echo &"Result: {result}"
-
-case fn:
-    of "input_04.txt":
-        assert result == 11787590
-    of "sample_input_04.txt":
-        assert result == 30