Merge pull request #576 from AlgorithmWithGod/lkhyun

[20250730] BOJ / G4 / 주난의 난 / 이강현

Author: ShinHeeEul

lkhyun/202507/30 BOJ G4 주난의 난.md

@@ -0,0 +1,81 @@
+```java
+import java.util.*;
+import java.io.*;
+
+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 char[][] room;
+    static int[] junan = new int[2];
+    static int[] friend = new int[2];
+    static int[] di = {0,0,-1,1};
+    static int[] dj = {-1,1,0,0};
+    public static void main(String[] args) throws Exception {
+        st = new StringTokenizer(br.readLine());
+        N = Integer.parseInt(st.nextToken());
+        M = Integer.parseInt(st.nextToken());
+        room = new char[N+1][M+1];
+
+        st = new StringTokenizer(br.readLine());
+        junan[0] = Integer.parseInt(st.nextToken());
+        junan[1] = Integer.parseInt(st.nextToken());
+        friend[0] = Integer.parseInt(st.nextToken());
+        friend[1] = Integer.parseInt(st.nextToken());
+        if(junan[0] == friend[0] && junan[1] == friend[1]){
+            bw.write("0");
+            bw.close();
+            return;
+        }
+
+        for (int i = 1; i <= N; i++) {
+            String line = br.readLine();
+            for (int j = 1; j <= M; j++) {
+                room[i][j] = line.charAt(j-1);
+            }
+        }
+
+        bw.write(BFS()+"");
+        bw.close();
+    }
+    static int BFS(){
+        ArrayDeque<int[]> q = new ArrayDeque<>();
+        boolean[][] visited = new boolean[N+1][M+1];
+        q.offer(new int[]{junan[0],junan[1],1});
+        visited[junan[0]][junan[1]] = true;
+
+        while(!q.isEmpty()){
+            int[] cur = q.poll();
+            if(cur[0] == friend[0] && cur[1] == friend[1]){
+                return cur[2];
+            }
+            for (int k = 0; k < 4; k++) {
+                int ni = cur[0] + di[k];
+                int nj = cur[1] + dj[k];
+        
+                while (check(ni, nj, visited)){
+                    if(room[ni][nj] == '1'){
+                        room[ni][nj] = '0';
+                        q.offer(new int[]{ni,nj,cur[2]+1});
+                        visited[ni][nj] = true;
+                        break;
+                    }
+                    q.push(new int[]{ni,nj,cur[2]});
+                    visited[ni][nj] = true;
+                    ni += di[k];
+                    nj += dj[k];
+                }
+            }
+        }
+        return 0;
+    }
+    static boolean check(int ni,int nj,boolean[][] visited){
+        if(ni<=0 || ni>N || nj<=0 || nj>M || visited[ni][nj]){
+            return false;
+        }else{
+            return true;
+        }
+    }
+}
+```