forward and back maps created

5/index.js

@@ -0,0 +1,43 @@
+const fs = require("fs");
+const inputRules = fs.readFileSync("input1.txt", "utf-8");
+const inputPages = fs.readFileSync("input2.txt", "utf-8");
+
+const rulesMapForward = new Map();
+const rulesMapBackward = new Map();
+
+function loadTree() {
+  //split the rules into an array of lines
+  const inputRulesArr = inputRules.split("\n");
+
+  //load forward rules
+  for (line of inputRulesArr) {
+    //split the lines into a first and second part
+    const [firstPage, secondPage] = line.split("|");
+    //if the rule doesnt exist yet create it
+    if (!rulesMapForward.has(firstPage)) {
+      rulesMapForward.set(firstPage, []);
+    }
+    //add the second page into a array stored in the map
+    const prevArray = rulesMapForward.get(firstPage);
+    rulesMapForward.set(firstPage, [...prevArray, secondPage]);
+  }
+
+  //load backword rules
+  for (line of inputRulesArr) {
+    //split the lines into a first and second part
+    const [firstPage, secondPage] = line.split("|");
+    //if the rule doesnt exist yet create it
+    if (!rulesMapBackward.has(secondPage)) {
+      rulesMapBackward.set(secondPage, []);
+    }
+    //add the second page into a array stored in the map
+    const prevArray = rulesMapBackward.get(secondPage);
+    rulesMapBackward.set(secondPage, [...prevArray, firstPage]);
+  }
+}
+
+loadTree();
+
+console.log(rulesMapForward);
+console.log("------------------");
+console.log(rulesMapBackward);