Merge pull request #82 from jktam336/jktam336/210-Course-Schedule-II

neetcode-gh · web-flow · commit 9acf325f2783 · 2022-04-06T19:42:52.000-07:00
Added JS 210-Course-Schedule-II
diff --git a/javascript/210-Course-Schedule-II.js b/javascript/210-Course-Schedule-II.js
@@ -0,0 +1,36 @@
+/**
+ * @param {number} numCourses
+ * @param {number[][]} prerequisites
+ * @return {number[]}
+ */
+ var findOrder = function(numCourses, prerequisites) {
+	const prereq = [];
+	for (let i = 0; i < numCourses; i++) {
+		prereq[i] = [];
+	};
+  for (const [crs, pre] of prerequisites) {
+    prereq[crs].push(pre);
+  };
+  
+	const output = [];
+  const visit = new Set();
+  const cycle = new Set();
+	function dfs(course) {
+    if (cycle.has(course)) return false;
+    if (visit.has(course)) return true;
+    
+    cycle.add(course);
+    for (const pre of prereq[course]) {
+      if (!dfs(pre)) return false;
+    }
+    cycle.delete(course);
+    visit.add(course);
+    output.push(course);
+    return true;
+	};
+
+	for (let j = 0; j < numCourses; j++) {
+		if (!dfs(j)) return [];
+	};
+	return output;
+};
