DFS와 BFS

week4/graph_traversal/DFS와_BFS/otter2023.java

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+import java.io.*;
+import java.util.*;
+
+public class Main {
+
+    static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+    static int n, m, v;
+    static List<Integer>[] edge;
+    static boolean[] visited;
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
+
+        StringTokenizer st = new StringTokenizer(bf.readLine());
+        n = Integer.parseInt(st.nextToken());
+        m = Integer.parseInt(st.nextToken());
+        v = Integer.parseInt(st.nextToken());
+
+        edge = new ArrayList[n + 1];
+
+        for (int i = 1; i <= n; i++) {
+            edge[i] = new ArrayList<>();
+        }
+
+        visited = new boolean[n + 1];
+
+        for (int i = 0; i < m; i++) {
+            st = new StringTokenizer(bf.readLine());
+            int a = Integer.parseInt(st.nextToken());
+            int b = Integer.parseInt(st.nextToken());
+            edge[a].add(b);
+            edge[b].add(a);
+        }
+
+        for (int i = 1; i <= n; i++) {
+            Collections.sort(edge[i]);
+        }
+
+        dfs(v);
+        bw.write("\n");
+
+        for (int i = 1; i <= n; i++) {
+            visited[i] = false;
+        }
+
+        bfs(v);
+
+        bw.flush();
+        bw.close();
+    }
+
+    static void dfs(int node) throws IOException {
+
+        visited[node] = true;
+        bw.write(node + " ");
+
+        for (int x : edge[node]) {
+            if (!visited[x]) {
+                dfs(x);
+            }
+        }
+    }
+
+    static void bfs(int node) throws IOException {
+
+        Queue<Integer> queue = new LinkedList<>();
+        queue.add(node);
+        visited[node] = true;
+
+        while(!queue.isEmpty()){
+            int current = queue.poll(); // 꺼내기
+            bw.write(current + " ");
+
+            for (int x : edge[current]) {
+                if (!visited[x]) {
+                    visited[x] = true;
+                    queue.add(x);
+                }
+            }
+        }
+
+    }
+
+}