Create Reachable Nodes With Restrictions.java

Author: varunu28

Medium/Reachable Nodes With Restrictions.java

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+class Solution {
+  public int reachableNodes(int n, int[][] edges, int[] restricted) {
+    Map<Integer, List<Integer>> graph = new HashMap<>();
+    for (int[] edge : edges) {
+      graph.computeIfAbsent(edge[0], k -> new ArrayList<>()).add(edge[1]);
+      graph.computeIfAbsent(edge[1], k -> new ArrayList<>()).add(edge[0]);
+    }
+    Set<Integer> restrictedSet = Arrays.stream(restricted).boxed().collect(Collectors.toSet());
+    Set<Integer> visited = new HashSet<>();
+    Queue<Integer> queue = new LinkedList<>();
+    queue.add(0);
+    visited.add(0);
+    while (!queue.isEmpty()) {
+      int size = queue.size();
+      while (size-- > 0) {
+        int node = queue.remove();
+        for (Integer neighbor : graph.getOrDefault(node, new ArrayList<>())) {
+          if (restrictedSet.contains(neighbor) || visited.contains(neighbor)) {
+            continue;
+          }
+          queue.add(neighbor);
+          visited.add(neighbor);
+        }
+      }
+    }
+    return visited.size();
+  }
+}