1 files changed, 45 insertions, 0 deletions
diff --git a/2020/09/solve.js b/2020/09/solve.js
new file mode 100644
index 0000000..394bd4b
--- /dev/null
+++ b/2020/09/solve.js
@@ -0,0 +1,45 @@
+const fs = require("fs");
+const data = fs
+  .readFileSync("input", "utf8")
+  .split("\n")
+  .map((x) => parseInt(x));
+
+function partOne() {
+  for (var i = 25; i < data.length; i++) {
+    const prev = data.slice(i - 25, i);
+    let correct = false;
+    for (let x = 0; x < prev.length; x++) {
+      for (let y = 0; y < prev.length; y++) {
+        if (prev[x] + prev[y] === data[i]) {
+          correct = true;
+          break;
+        }
+      }
+      if (correct) break;
+    }
+
+    if (!correct) return data[i];
+  }
+  return 0;
+}
+
+function partTwo(num) {
+  for (let i = 0; i < data.length; i++) {
+    let cnt = 0;
+    let j = i;
+    for (; j < data.length; j++) {
+      cnt += data[j];
+      if (cnt >= num) break;
+    }
+    if (cnt == num) {
+      const range = data.slice(i, j + 1);
+      return Math.min(...range) + Math.max(...range);
+    } else {
+      cnt = 0;
+    }
+  }
+}
+
+const num = partOne();
+console.log(num);
+console.log(partTwo(num));