2022 Day 2 Nim

2022/day2.nim

@@ -0,0 +1,28 @@
+from std/math import floorMod
+import sequtils
+import strutils
+import tables
+
+proc `%%` (a: int, b: int): int = floorMod(a, b)
+
+let moveMap = {'A': 1, 'B': 2, 'C': 3, 'X': 1, 'Y': 2, 'Z': 3}.toTable
+let rounds = splitlines strip readFile "day2-input"
+
+# Part 1
+proc round1Score(round: string): int =
+    let them = moveMap[round[0]]
+    let us = moveMap[round[2]]
+    let winScore = [3, 6, 0][(us - them) %% 3]
+    us + winScore
+
+echo rounds.map(round1Score).foldl(a + b)
+
+# Part 2
+proc round2Score(round: string): int =
+    let them: int = moveMap[round[0]]
+    let usDelta = moveMap[round[2]] - 2
+    let us: int = ((them + usDelta - 1) %% 3) + 1
+    let winScore = [3, 6, 0][(us - them) %% 3]
+    us + winScore
+
+echo rounds.map(round2Score).foldl(a + b)