[20250908] BOJ / G4 / 알고스팟 / 이강현

Author: lkhyun

lkhyun/202509/08 BOJ G4 알고스팟.md

@@ -0,0 +1,58 @@
+```java
+import java.io.*;
+import java.util.*;
+
+public class Main {
+    static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+    static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+    static StringTokenizer st;
+    static int N,M;
+    static int[] di = {-1,1,0,0};
+    static int[] dj = {0,0,-1,1};
+    static int[][] matrix;
+
+    public static void main(String[] args) throws IOException {
+        st = new StringTokenizer(br.readLine());
+        M = Integer.parseInt(st.nextToken());
+        N = Integer.parseInt(st.nextToken());
+
+        matrix = new int[N][M];
+        for (int i = 0; i < N; i++) {
+            String line = br.readLine();
+            for (int j = 0; j < M; j++) {
+                matrix[i][j] = Character.getNumericValue(line.charAt(j));
+            }
+        }
+        bw.write(BFS()+"");
+        bw.close();
+    }
+    public static int BFS(){
+        ArrayDeque<int[]> deq = new ArrayDeque<>();
+        boolean[][] visited = new boolean[N][M];
+        deq.offer(new int[]{0,0,0});
+        visited[0][0] = true;
+
+        while(!deq.isEmpty()){
+            int[] cur = deq.poll();
+            
+            if(cur[0] == N-1 && cur[1] == M-1) return cur[2];
+
+            for (int i = 0; i < 4; i++) {
+                int ni = cur[0] + di[i];
+                int nj = cur[1] + dj[i];
+
+                if(ni<0 || ni>=N || nj<0 || nj>=M || visited[ni][nj]) continue;
+
+                if(matrix[ni][nj] == 0){
+                    deq.offerFirst(new int[]{ni,nj,cur[2]});
+                    visited[ni][nj] = true;
+                }else{
+                    deq.offer(new int[]{ni,nj,cur[2]+1});
+                    visited[ni][nj] = true;
+                }
+            }
+        }
+        return 0;
+    }
+}
+```