Time: 83 ms (42.13%), Space: 59.7 MB (57.49%) - LeetHub

Author: chappdev2019

1558-course-schedule-iv/1558-course-schedule-iv.js

@@ -0,0 +1,35 @@
+function checkIfPrerequisite(numCourses, prerequisites, queries) {
+    let map = new Map();
+
+    for (let i = 0; i < prerequisites.length; i++) {
+        let course = prerequisites[i][0];
+        let prereq = prerequisites[i][1];
+        if (!map.has(course)) {
+            map.set(course, new Set());
+        }
+        map.get(course).add(prereq);
+    }
+
+    let reachable = Array.from({ length: numCourses }, () => Array(numCourses).fill(false));
+    for (let [course, prereqs] of map) {
+        for (let prereq of prereqs) {
+            reachable[course][prereq] = true;
+        }
+    }
+    for (let k = 0; k < numCourses; k++) {
+        for (let i = 0; i < numCourses; i++) {
+            for (let j = 0; j < numCourses; j++) {
+                reachable[i][j] = reachable[i][j] || (reachable[i][k] && reachable[k][j]);
+            }
+        }
+    }
+
+    let res = [];
+    for (let i = 0; i < queries.length; i++) {
+        let course = queries[i][0];
+        let prereq = queries[i][1];
+        res.push(reachable[course][prereq]);
+    }
+
+    return res;
+}