1 files changed, 32 insertions, 0 deletions
diff --git a/2022/21/solve.js b/2022/21/solve.js
new file mode 100644
index 0000000..818e463
--- /dev/null
+++ b/2022/21/solve.js
@@ -0,0 +1,32 @@
+d=require("fs").readFileSync("input", "utf8").trimEnd().split("\n").map(s=>s.split(": ")).reduce((a,s)=>({...a,[s[0]]:s[1].split(/ ([+|\-|*|/]) /)}),{})
+
+r=m=>isNaN(d[m])?eval(r(d[m][0])+d[m][1]+r(d[m][2])):d[m]
+
+function part1()
+{
+	return r("root")
+}
+
+function part2()
+{
+	// small binary search
+	// i'm sure there are better ways.. but it works
+	d["root"][1] = "-"
+	low = 1e2
+	high = 1e20
+	while (low != high) {
+		mid = (low + high)/2
+		d["humn"][0] = `${mid}`
+		score = 0 - r("root")
+		if (score < 0) low = mid
+		else if (score == 0) return mid
+		else high = mid
+	}
+	return 0
+}
+
+const tic = performance.now();
+console.log(part1());
+console.log(part2());
+const toc = performance.now();
+console.log("TIME: " + ((toc - tic) / 1000).toFixed(6) + " seconds");