[BOJ/PGS] 14주차 임건애

Java/임건애/[Week 14]DFS,BFS/[BOJ] DFS와 BFS_1260_실버2.java

@@ -0,0 +1,73 @@
+import java.util.*;
+import java.io.*;
+
+class Main
+{
+    static int N, M, V;
+    static int[][] graph;
+    static boolean[] visited;
+    static StringBuilder sb;
+
+	public static void main (String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+
+        N = Integer.parseInt(st.nextToken());
+        M = Integer.parseInt(st.nextToken());
+        V = Integer.parseInt(st.nextToken());
+
+        graph = new int[N + 1][N + 1];
+
+        // 그래프 정보 저장
+        for (int i = 0; i < M; i++) {
+            st = new StringTokenizer(br.readLine());
+            int a = Integer.parseInt(st.nextToken());
+            int b = Integer.parseInt(st.nextToken());
+
+            graph[a][b] = 1;
+            graph[b][a] = 1;
+        }
+
+        visited = new boolean[N + 1];
+        sb = new StringBuilder();
+        DFS(V);
+        System.out.println(sb.toString());
+
+        visited = new boolean[N + 1];
+        sb = new StringBuilder();
+        BFS(V);
+        System.out.println(sb.toString());
+	}
+
+
+	public static void DFS(int start) {
+	    visited[start] = true;
+	    sb.append(start).append(' ');
+
+	    for (int next = 1; next <= N; next++) {
+	        if (graph[start][next] == 1 && !visited[next]) {
+                DFS(next);
+            }
+	    }
+	}
+
+	public static void BFS(int start) {
+	    Queue<Integer> q = new LinkedList<>();
+	    visited[start] = true;
+	    q.add(start);
+
+	    while (!q.isEmpty()) {
+	        int n = q.poll();
+	        sb.append(n).append(' ');
+
+	        for (int next = 1; next <= N; next++) {
+                if (graph[n][next] == 1 && !visited[next]) {
+                    visited[next] = true;
+                    q.add(next);
+                }
+            }
+        }
+
+	}
+
+}

Java/임건애/[Week 14]DFS,BFS/[BOJ] 숨바꼭질_1697_실버1.java

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+import java.io.*;
+import java.util.*;
+
+class Main {
+    static final int MAX = 100000;
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+
+        int N = Integer.parseInt(st.nextToken());
+        int K = Integer.parseInt(st.nextToken());
+
+        if (N >= K) {
+            System.out.println(N - K);
+            return;
+        }
+
+        boolean[] visited = new boolean[MAX + 1];
+        int[] arr = new int[MAX + 1];
+
+        Queue<Integer> q = new LinkedList<>();
+        visited[N] = true;
+        q.add(N);
+
+        while (!q.isEmpty()) {
+            int start = q.poll();
+
+            if (start == K) {
+                System.out.println(arr[start]);
+                return;
+            }
+
+            int[] next = {start - 1, start + 1, start * 2};
+            for (int n : next) {
+                if (0 <= n && n <= MAX && !visited[n]) {
+                    visited[n] = true;
+                    arr[n] = arr[start] + 1;
+                    q.add(n);
+                }
+            }
+        }
+
+    }
+
+}

Java/임건애/[Week 14]DFS,BFS/[PGS] 네트워크_43162_LV3.java

@@ -0,0 +1,25 @@
+class Solution {
+    public int solution(int n, int[][] computers) {
+        int answer = 0;
+        boolean[] visited = new boolean[n];
+
+        for (int i = 0; i < n; i++) {
+            if (!visited[i]) {
+                DFS(i, n, computers, visited);
+                answer++;
+            }
+        }
+
+        return answer;
+    }
+
+    private void DFS(int start, int n, int[][] computers, boolean[] visited) {
+        visited[start] = true;
+        for (int next = 0; next < n; next++) {
+            if (computers[start][next] == 1 && !visited[next]) {
+                DFS(next, n, computers, visited);
+            }
+        }
+    }
+
+}