split history into difference sequences

Day9/Part1.js

@@ -1,8 +1,24 @@
 import { readFileSync } from "fs";
 const t0 = performance.now();
 
-const input = readFileSync("input.txt").toString();
+const input = readFileSync("input.txt")
-console.log(input);
+	.toString()
+	.split("\n")
+	.filter((e) => e.length > 0);
+const histories = input.map((e) => e.split(" ").map(Number));
+const sequences = [];
+let current = histories[0];
+while (!current.every((e) => e === 0)) {
+	sequences.push(current);
+	current = current.reduce((a, n, i) => {
+		if (i === 0) return a;
+		const d = n - current[i - 1];
+		const t = a;
+		t.push(d);
+		return t;
+	}, []);
+}
+console.log(sequences);
 
 const t1 = performance.now();
 console.log(`Runtime: ${t1 - t0}ms`);