[BOJ, PGS] 14주차 주민경

Java/주민경/[week14] BFS, DFS/[BOJ] BFS와 DFS_1260_실버2.java

@@ -0,0 +1,65 @@
+import java.io.*;
+import java.util.*;
+
+public class Main {
+    public static void main(String[] args) throws IOException {
+        BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(bf.readLine());
+        int N = Integer.parseInt(st.nextToken());
+        int M = Integer.parseInt(st.nextToken());
+        int V = Integer.parseInt(st.nextToken());
+
+        List<List<Integer>> graph = new ArrayList<>();
+        for (int i = 0; i <= N; i++) {
+            graph.add(new ArrayList<>());
+        }
+
+        for (int i = 0; i < M; i++) {
+            st = new StringTokenizer(bf.readLine());
+            int u = Integer.parseInt(st.nextToken());
+            int v = Integer.parseInt(st.nextToken());
+            graph.get(u).add(v);
+            graph.get(v).add(u);
+        }
+
+        for (int i = 1; i <= N; i++) {
+            Collections.sort(graph.get(i));
+        }
+
+        boolean[] visited = new boolean[N + 1];
+        DFS(graph, V, visited);
+        System.out.println();
+
+        visited = new boolean[N + 1];
+        BFS(graph, V, visited);
+    }
+
+    // DFS
+    public static void DFS(List<List<Integer>> graph, int v, boolean[] visited) {
+        visited[v] = true;
+        System.out.print(v + " ");
+        for (int next : graph.get(v)) {
+            if (!visited[next]) {
+                DFS(graph, next, visited);
+            }
+        }
+    }
+
+    // BFS
+    public static void BFS(List<List<Integer>> graph, int start, boolean[] visited) {
+        Queue<Integer> q = new LinkedList<>();
+        q.add(start);
+        visited[start] = true;
+
+        while (!q.isEmpty()) {
+            int v = q.poll();
+            System.out.print(v + " ");
+            for (int next : graph.get(v)) {
+                if (!visited[next]) {
+                    visited[next] = true;
+                    q.add(next);
+                }
+            }
+        }
+    }
+}

Java/주민경/[week14] BFS, DFS/[BOJ] 숨바꼭질_1697_실버1.java

@@ -0,0 +1,35 @@
+import java.util.*;
+import java.lang.*;
+import java.io.*;
+
+class Main
+{
+	public static void main (String[] args) throws IOException
+	{
+	    Scanner sc = new Scanner(System.in);
+	    int N = sc.nextInt(); // 수빈이가 있는 위치
+	    int K = sc.nextInt(); // 동생이 있는 위치 
+
+	    boolean[] visited = new boolean[100001];
+	    Queue<int[]> queue = new LinkedList<>();
+	    queue.offer(new int[]{N, 0});
+
+	    while (!queue.isEmpty()) {
+	        int[] cur = queue.poll();
+	        int p = cur[0];
+	        int count = cur[1];
+
+	        if (p == K) {
+	            System.out.println(count);
+	            break;
+	        }
+
+	        for (int next: new int[]{p-1, p+1, 2*p}) {
+	            if (next >= 0 && next <= 100000 && !visited[next]) {
+	               visited[next] = true;
+	               queue.offer(new int[]{next, count+1});
+	            }
+	        }
+	    }
+	}
+}

Java/주민경/[week14] BFS, DFS/[PGS] 게임맵최단거리_1844_Lv.3.java

@@ -0,0 +1,41 @@
+import java.util.*;
+
+class Solution {
+    public int solution(int[][] maps) {
+        int answer = -1;
+        int n = maps.length;
+        int m = maps[0].length;
+        boolean[][] visited = new boolean[n][m];
+        int[][] direction = {
+            {1, 0},
+            {-1, 0},
+            {0, -1}, 
+            {0, 1}
+        };
+        Queue<int[]> queue = new LinkedList<>();
+        queue.offer(new int[]{0,0,0});
+
+        while(!queue.isEmpty()) {
+            int[] next = queue.poll();
+
+            if (next[0] == n-1 && next[1] == m-1) {
+                answer = next[2] + 1;
+                System.out.println(answer);
+                break;
+            }
+
+            for (int i = 0; i < direction.length; i++) {
+                int dx = direction[i][0] + next[0];
+                int dy = direction[i][1] + next[1];
+                int count = next[2];
+
+                if (dx >= 0 && dy >= 0 && dx < n && dy < m && maps[dx][dy] == 1 && !visited[dx][dy]) {
+                    queue.offer(new int[]{dx, dy, count+1});
+                    visited[dx][dy] = true;
+
+                }
+            }
+        }
+        return answer;
+    }
+}

Java/주민경/[week14] BFS, DFS/[PGS] 네트워크_43162_Lv.3.java

@@ -0,0 +1,32 @@
+import java.util.*;
+
+class Solution {
+    public int solution(int n, int[][] computers) {
+        int answer = 0;
+        Queue<Integer> q = new LinkedList<>();
+        boolean[] visited = new boolean[n+1];
+
+        for (int s = 0 ; s < n; s++) {
+            if (!visited[s+1]) {
+                q.offer(s+1);
+                while(!q.isEmpty()) {
+                    int next = q.poll();
+
+                    for (int i = 1; i <= n; i++) {
+                        if (computers[next-1][i-1] == 1 && !visited[i]) {
+                        q.offer(i);
+                        visited[i] = true;
+                        }   
+                    }
+
+                }
+                answer++;
+            }
+
+        }
+
+
+
+        return answer;
+    }
+}