feat: 알고리즘 문제 풀이

dlwnsgus777 · Nov 29, 2022 · f184519 · f184519
1 parent 37331d6
commit f184519
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Showing 4 changed files with 205 additions and 5 deletions.
diff --git a/baekjoon/src/main/java/baekjoon/dfs_bfs/DFS와BFS.java b/baekjoon/src/main/java/baekjoon/dfs_bfs/DFS와BFS.java
@@ -3,25 +3,71 @@
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStreamReader;
+import java.util.Arrays;
+import java.util.LinkedList;
+import java.util.Queue;
 
 public class DFS와BFS {
    static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+   static boolean[] visited;
+   static int[][] graph;
    public static void main(String[] args) throws IOException {
       String[] arr = br.readLine().split(" ");
 
       int n = Integer.parseInt(arr[0]);
-      int m = Integer.parseInt(arr[0]);
-      int startIndex = Integer.parseInt(arr[0]);
+      int m = Integer.parseInt(arr[1]);
+      int startIndex = Integer.parseInt(arr[2]);
 
-      int[][] graph = new int[][]
+      graph = new int[n + 1][n + 1];
 
+      visited = new boolean[n + 1];
+
+      for (int i = 0; i < m; i++) {
+         String[] node = br.readLine().split(" ");
+         int a = Integer.parseInt(node[0]);
+         int b = Integer.parseInt(node[1]);
+
+         graph[a][b] = graph[b][a] = 1;
+      }
+
+      dfs(startIndex);
+
+      System.out.println();
+
+      Arrays.fill(visited, false);
+
+      bfs(startIndex);
    }
 
-   private void dfs(int nodeIndex) {
+   private static void dfs(int nodeIndex) {
+      visited[nodeIndex] = true;
+
+      System.out.print(nodeIndex + " ");
 
+      for (int i = 1; i < graph.length; i++) {
+         if(graph[nodeIndex][i] == 1 && !visited[i]) {
+            dfs(i);
+         }
+      }
    }
 
-   private void bfs(int nodeIndex) {
+   private static void bfs(int nodeIndex) {
+      Queue<Integer> queue = new LinkedList<>();
+
+      queue.add(nodeIndex);
+      visited[nodeIndex] = true;
+      System.out.print(nodeIndex + " ");
+
+      while (!queue.isEmpty()) {
+         int temp = queue.poll();
 
+         for (int i = 1; i < graph.length; i++) {
+            if (graph[temp][i] == 1 && !visited[i]) {
+               queue.add(i);
+               visited[i] = true;
+               System.out.print(i + " ");
+            }
+         }
+      }
    }
 }
diff --git a/baekjoon/src/main/java/baekjoon/dfs_bfs/바닥장식.java b/baekjoon/src/main/java/baekjoon/dfs_bfs/바닥장식.java
@@ -0,0 +1,55 @@
+package baekjoon.dfs_bfs;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.nio.Buffer;
+
+public class 바닥장식 {
+   static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+   static String[][] graph;
+
+   public static void main(String[] args) throws IOException {
+      String[] arr = br.readLine().split(" ");
+
+      int n = Integer.parseInt(arr[0]);
+      int m = Integer.parseInt(arr[1]);
+
+      graph = new String[n][m];
+
+      for (int i = 0; i < n; i++) {
+         char[] tile = br.readLine().toCharArray();
+
+         for (int j = 0; j < m; j++) {
+            graph[i][j] = String.valueOf(tile[j]);
+         }
+      }
+
+      System.out.println("*************************");
+      int count = 0;
+
+      for (int i = 0; i < graph.length; i++) {
+         int tmp = 0;
+         for (int j = 0; j < graph[i].length; j++) {
+            if (graph[i][j].equals("|")) {
+               tmp = 0;
+            } else {
+               count++;
+            }
+         }
+      }
+
+      for (int i = 0; i < graph.length; i++) {
+         int tmp = 0;
+         for (int j = 0; j < graph[i].length; j++) {
+            if (graph[j][i].equals("-")) {
+               tmp = 0;
+            } else {
+               count++;
+            }
+         }
+      }
+
+      System.out.println(count);
+   }
+}
diff --git a/baekjoon/src/main/java/baekjoon/dfs_bfs/바이러스.java b/baekjoon/src/main/java/baekjoon/dfs_bfs/바이러스.java
@@ -0,0 +1,47 @@
+package baekjoon.dfs_bfs;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+
+public class 바이러스 {
+   static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+   static int[][] graph;
+   static boolean[] visited;
+   static int result;
+
+   public static void main(String[] args) throws IOException {
+      int n = Integer.parseInt(br.readLine());
+      int m = Integer.parseInt(br.readLine());
+
+      graph = new int[n + 1][n + 1];
+      visited = new boolean[n + 1];
+
+      int startIndex = 1;
+
+      result = 0;
+
+      for (int i = 0; i < m; i++) {
+         String[] arr = br.readLine().split(" ");
+         int a = Integer.parseInt(arr[0]);
+         int b = Integer.parseInt(arr[1]);
+
+         graph[a][b] = graph[b][a] = 1;
+      }
+
+      dfs(startIndex);
+
+      System.out.println(result);
+   }
+
+   static void dfs(int startIndex) {
+      visited[startIndex] = true;
+
+      for (int i = 1; i < graph.length; i++) {
+         if (graph[startIndex][i] == 1 && !visited[i]) {
+            result++;
+            dfs(i);
+         }
+      }
+   }
+}
diff --git a/baekjoon/src/main/java/baekjoon/dfs_bfs/한동이.java b/baekjoon/src/main/java/baekjoon/dfs_bfs/한동이.java
@@ -0,0 +1,52 @@
+package baekjoon.dfs_bfs;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.Arrays;
+
+// TODO: 틀림....
+public class 한동이 {
+   static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+   static int[] graph;
+   static boolean[] visited;
+   static int result;
+   static int count;
+   static int temp;
+   public static void main(String[] args) throws IOException {
+      int n = Integer.parseInt(br.readLine());
+
+      graph = new int[n + 1];
+      visited = new boolean[n + 1];
+      temp = Integer.MIN_VALUE;
+
+      for (int i = 1; i < graph.length; i++) {
+         graph[i] = Integer.parseInt(br.readLine());
+      }
+
+      for (int i = 1; i <= n; i++) {
+         visited = new boolean[n + 1];
+         dfs(i);
+
+         if (temp < count) {
+            temp = count;
+            result = i;
+         }
+
+         count = 0;
+      }
+
+      System.out.println(result);
+   }
+
+   static void dfs(int startIdx) {
+      visited[startIdx] = true;
+
+      for (int i = 1; i < graph.length; i++) {
+         if (!visited[graph[i]]) {
+            count++;
+            dfs(graph[i]);
+         }
+      }
+   }
+}