feat(day-2): dumb part 1 solution

1 files changed, 49 insertions, 0 deletions

diff --git a/day-2/index.js b/day-2/index.js
new file mode 100644
index 0000000..3671a9b
--- /dev/null
+++ b/day-2/index.js
@@ -0,0 +1,49 @@
+const fs = require('fs');
+const input = fs.readFileSync('./day-2/input.txt').toString();
+
+const lines = input.split('\n');
+
+const [ROCK, PAPER, SCISSORS] = ['rock', 'paper', 'scissors'];
+const [LOSS, WIN, DRAW] = ['loss', 'win', 'draw'];
+
+const defeatMap = { // What defeats what
+  [ROCK]: SCISSORS,
+  [SCISSORS]: PAPER,
+  [PAPER]: ROCK,
+}
+
+const shapeMap = {
+  A: ROCK,
+  B: PAPER,
+  C: SCISSORS,
+
+  X: ROCK,
+  Y: PAPER,
+  Z: SCISSORS,
+}
+
+const shapeScores = {
+  [ROCK]: 1,
+  [PAPER]: 2,
+  [SCISSORS]: 3,
+};
+
+const outcomeScores = {
+  [LOSS]: 0,
+  [DRAW]: 3,
+  [WIN]: 6
+};
+
+const result = lines.reduce((acc, line) => {
+  const [opponentShape, shape] = line.split(' ').map(code => shapeMap[code]);
+  if (!shape || !opponentShape) return acc;
+
+  let outcome = LOSS;
+  if (shape === opponentShape) outcome = DRAW;
+  else if (defeatMap[shape] === opponentShape) outcome = WIN;
+
+  return acc + shapeScores[shape] + outcomeScores[outcome];
+}, 0)
+
+console.log(result);
+