Solutions for day three

03/code.js

@@ -0,0 +1,77 @@
+const fs = require('fs');
+const inputArray = fs.readFileSync('input.txt').toString().split("\n");
+
+// Part One
+
+const lines = inputArray.length;
+const oneCount = [];
+for (i in inputArray[0]) {
+  oneCount[i] = 0;
+}
+const gammaArray = Object.assign([], oneCount);
+const epsilonArray = Object.assign([], oneCount);
+
+
+for(i in inputArray) {
+  const line = inputArray[i];
+  for (x in line) {
+    if (line[x] === "1") {
+      oneCount[x]++;
+    }
+  }
+}
+
+for (i in oneCount) {
+  if (oneCount[i] > (lines / 2)) {
+    gammaArray[i] = 1;
+  } else {
+    epsilonArray[i] = 1;
+  }
+}
+const gamma = parseInt(gammaArray.join(""), 2);
+const epsilon = parseInt(epsilonArray.join(""), 2);
+
+console.log(`${gamma} * ${epsilon} = ${gamma * epsilon}`);
+
+// Part Two
+
+function arrayFilter(unfilteredArray, testChar, rating) {
+
+  if (unfilteredArray.length === 1) {
+    return unfilteredArray;
+  }
+
+  let count = 0;
+  let greatest = "0";
+  const lines = unfilteredArray.length;
+  for(i in unfilteredArray) {
+    count = count + parseInt(unfilteredArray[i][testChar]);
+  }
+
+  if (count >= (lines / 2)) {
+    greatest = "1";
+  }
+
+  if (rating === "oxygen") {
+    filteredArray = unfilteredArray.filter(line => line[testChar] === greatest)
+  } else {
+    filteredArray = unfilteredArray.filter(line => line[testChar] !== greatest)
+  }
+
+  return filteredArray;
+}
+
+let oxygenRatingArray = Object.assign([], inputArray);
+let co2RatingArray = Object.assign([], inputArray);
+
+for (x in oxygenRatingArray[0]) {
+  oxygenRatingArray = arrayFilter(oxygenRatingArray, x, "oxygen")
+}
+
+for (x in co2RatingArray[0]) {
+  co2RatingArray = arrayFilter(co2RatingArray, x, "co2")
+}
+
+const oxygen = parseInt(oxygenRatingArray.join(""), 2);
+const co2 = parseInt(co2RatingArray.join(""), 2);
+console.log(`${oxygen} * ${co2} = ${oxygen * co2}`);