2368. Reachable Nodes With Restrictions

Author: zhaoguanchen

README.md

@@ -277,6 +277,7 @@ The project is divided into two parts: `structure` and `solution`.
 | 277  | [Find the Celebrity](https://leetcode.com/problems/find-the-celebrity/) | Medium     | [FindTheCelebrity.java](src/leetcode/solution/Graph/FindTheCelebrity.java) | - Logical Deduction                                          |
 | 310  | [Minimum Height Trees](https://leetcode.com/problems/minimum-height-trees/) | Medium     | [MinimumHeightTrees.java](src/leetcode/solution/Graph/MinimumHeightTrees.java) | - BFS: remove leaves                                         |
 | 1192 | [Critical Connections in a Network](https://leetcode.com/problems/critical-connections-in-a-network/) | Hard       | [CriticalConnectionsInANetwork.java](src/leetcode/solution/Graph/CriticalConnectionsInANetwork.java) | - DFS: find cycle and remove the edge.                       |
+| 2368 | [Reachable Nodes With Restrictions](https://leetcode.com/problems/reachable-nodes-with-restrictions/) | Medium     | [ReachableNodesWithRestrictions.java](src/leetcode/solution/Graph/ReachableNodesWithRestrictions.java) | - DFS.                                                       |
 
 
 

src/leetcode/solution/Graph/ReachableNodesWithRestrictions.java

@@ -0,0 +1,74 @@
+package leetcode.solution.Graph;
+
+import java.util.*;
+
+/**
+ * 2368. Reachable Nodes With Restrictions
+ */
+public class ReachableNodesWithRestrictions {
+
+    public static void main(String[] args) {
+        ReachableNodesWithRestrictionsSolution solution = new ReachableNodesWithRestrictionsSolution();
+        int n = 7;
+        int[][] edges = new int[][]{{0, 1}, {0, 2}, {0, 5}, {0, 4}, {3, 2}, {6, 5}};
+        int[] restricted = new int[]{4, 2, 1};
+
+        System.out.println(solution.reachableNodes(n, edges, restricted));
+        // 3
+    }
+
+}
+
+
+class ReachableNodesWithRestrictionsSolution {
+
+    private List<List<Integer>> graph;
+    private Set<Integer> set;
+    private int count;
+
+    public int reachableNodes(int n, int[][] edges, int[] restricted) {
+        this.graph = build(n, edges);
+        this.set = new HashSet<>();
+
+        for (int num : restricted) {
+            set.add(num);
+        }
+
+        this.count = 0;
+
+        dfs(0);
+
+        return count;
+    }
+
+    private void dfs(int node) {
+        if (set.contains(node)) {
+            return;
+        }
+
+        count++;
+        set.add(node);
+
+        List<Integer> nei = graph.get(node);
+
+        for (int next : nei) {
+            dfs(next);
+        }
+
+    }
+
+    private List<List<Integer>> build(int n, int[][] edges) {
+        List<List<Integer>> list = new ArrayList<>();
+
+        for (int i = 0; i < n; i++) {
+            list.add(new ArrayList<>());
+        }
+
+        for (int[] edge : edges) {
+            list.get(edge[0]).add(edge[1]);
+            list.get(edge[1]).add(edge[0]);
+        }
+
+        return list;
+    }
+}