[20250625] BOJ / G1 / 구슬 탈출 2 / 이강현

lkhyun/202506/25 BOJ G1 구슬 탈출 2.md

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+```java
+import java.io.*;
+import java.util.*;
+
+public class Main {
+    static class state{
+        int[] red;
+        int[] blue;
+        int moveCnt;
+        state(int redi, int redj, int bluei, int bluej, int moveCnt){
+            this.red = new int[]{redi,redj};
+            this.blue = new int[]{bluei,bluej};
+            this.moveCnt = moveCnt;
+        }
+    }
+    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[][] board;
+    static int[] di = {-1,1,0,0};
+    static int[] dj = {0,0,-1,1};
+    static int[] red = new int[2];
+    static int[] blue = new int[2];
+    static int[] out = new int[2];
+
+    public static void main(String[] args) throws IOException {
+        st = new StringTokenizer(br.readLine());
+        N = Integer.parseInt(st.nextToken());
+        M = Integer.parseInt(st.nextToken());
+        board = new char[N][M];
+        for (int i = 0; i < N; i++) {
+            String line = br.readLine();
+            for (int j = 0; j < M; j++) {
+                board[i][j] = line.charAt(j);
+                if(board[i][j] == 'O'){
+                    out[0] = i;
+                    out[1] = j;
+                }else if(board[i][j] == 'B'){
+                    blue[0] = i;
+                    blue[1] = j;
+                }else if(board[i][j] == 'R'){
+                    red[0] = i;
+                    red[1] = j;
+                }
+            }
+        }
+        bw.write(BFS() + "");
+        bw.close();
+    }
+
+    static int[] moveMarble(int i, int j, int dir) {
+        int ni = i;
+        int nj = j;
+        int moveCnt = 0;
+        int reachedHole = 0;
+
+        while(true) {
+            ni += di[dir];
+            nj += dj[dir];
+            moveCnt++;
+
+            if(ni < 0 || ni >= N || nj < 0 || nj >= M || board[ni][nj] == '#') {
+                ni -= di[dir];
+                nj -= dj[dir];
+                moveCnt--;
+                break;
+            }
+
+            if(board[ni][nj] == 'O') {
+                reachedHole = 1;
+                break;
+            }
+        }
+
+        return new int[]{ni, nj, moveCnt, reachedHole};
+    }
+
+    static int BFS(){
+        int answer = -1;
+        ArrayDeque<state> q = new ArrayDeque<>();
+        q.add(new state(red[0],red[1],blue[0],blue[1],0));
+        boolean[][][][] visited = new boolean[N][M][N][M];
+        visited[red[0]][red[1]][blue[0]][blue[1]] = true;
+
+        loop: while(!q.isEmpty()){
+            state cur = q.poll();
+            if(cur.moveCnt >= 10) continue;
+
+            for (int k = 0; k < 4; k++) {
+                boolean redOut = false;
+                boolean blueOut = false;
+
+                int[] redResult = moveMarble(cur.red[0], cur.red[1], k);
+                int[] blueResult = moveMarble(cur.blue[0], cur.blue[1], k);
+
+                int ri = redResult[0];
+                int rj = redResult[1];
+                int redMoveCnt = redResult[2];
+                boolean redReachedHole = redResult[3] == 1;
+
+                int bi = blueResult[0];
+                int bj = blueResult[1];
+                int blueMoveCnt = blueResult[2];
+                boolean blueReachedHole = blueResult[3] == 1;
+
+                if(redReachedHole) redOut = true;
+                if(blueReachedHole) blueOut = true;
+
+                if(blueOut) continue;
+
+                if(redOut) {
+                    answer = cur.moveCnt + 1;
+                    break loop;
+                }
+
+                //충돌처리
+                if(ri == bi && rj == bj) {
+                    if(redMoveCnt > blueMoveCnt) {
+                        ri -= di[k];
+                        rj -= dj[k];
+                    } else {
+                        bi -= di[k];
+                        bj -= dj[k];
+                    }
+                }
+
+                if(!visited[ri][rj][bi][bj]){
+                    q.add(new state(ri,rj,bi,bj,cur.moveCnt+1));
+                    visited[ri][rj][bi][bj] = true;
+                }
+            }
+        }
+        return answer;
+    }
+}
+```