Update 1462-course-schedule-iv.js

Author: everthis

1462-course-schedule-iv.js

@@ -1,3 +1,61 @@
+/**
+ * @param {number} numCourses
+ * @param {number[][]} prerequisites
+ * @param {number[][]} queries
+ * @return {boolean[]}
+ */
+const checkIfPrerequisite = function (numCourses, prerequisites, queries) {
+  const n = numCourses, m = prerequisites.length
+  const graph = {}, inDegree = Array(n).fill(0)
+  
+  for(const [s, e] of prerequisites) {
+    if(graph[s] == null) graph[s] = []
+    inDegree[e]++
+    graph[s].push(e)
+  }
+  
+  let q = []
+  
+  for(let i = 0; i < n; i++) {
+    if(inDegree[i] === 0) q.push(i)
+  }
+  
+  const hash = {}
+
+  while(q.length) {
+    const size = q.length
+    const nxt = []
+    for(let i = 0; i < size; i++) {
+      const cur = q[i]
+      for(const e of (graph[cur] || [])) {
+        inDegree[e]--
+        if(hash[e] == null) hash[e] = new Set()
+        hash[e].add(cur)
+        for(const dep of (hash[cur] || [])) {
+          hash[e].add(dep)
+        }
+      
+        if(inDegree[e] === 0) {
+          nxt.push(e)
+        }
+      }
+    }
+    
+    q = nxt
+  }
+  
+  const res = []
+  for(const [p, e] of queries) {
+    if(hash[e] && hash[e].has(p)) res.push(true)
+    else res.push(false)
+  }
+  
+  return res
+}
+
+// another
+
+
 /**
  * @param {number} numCourses
  * @param {number[][]} prerequisites