1+ import java .io .*;
2+ import java .util .*;
3+ 4+ //bfs + 비트마스킹
5+ //처음에 dfs 로 접근했는데, 그럼 모든 경로를 다 탐색 해 버리더라구요 최단거리 문제는 bfs 로 풀기!
6+ public class YJ_1194 {
7+ static class Pos {
8+ int x ;
9+ int y ;
10+ int distance ;
11+ int hasKey ;
12+ 13+ public Pos (int x , int y , int distance , int hasKey ) {
14+ this .x = x ;
15+ this .y = y ;
16+ this .distance = distance ;
17+ this .hasKey = hasKey ;
18+ }
19+ }
20+ 21+ static final char EXIT = '1' ;
22+ static final char CURRENT = '0' ;
23+ static final char WALL = '#' ;
24+ 25+ static int N ;
26+ static int M ;
27+ static char [][] maze ;
28+ 29+ public static void main (String [] args ) throws IOException {
30+ BufferedReader br = new BufferedReader (new InputStreamReader (System .in ));
31+ StringTokenizer st = new StringTokenizer (br .readLine ());
32+ N = Integer .parseInt (st .nextToken ());
33+ M = Integer .parseInt (st .nextToken ());
34+ maze = new char [N ][M ];
35+ visited = new boolean [N ][M ][64 ]; //★키 6개 2^6 = 64
36+ 37+ int x = 0 ;
38+ int y = 0 ;
39+ for (int i =0 ; i <N ; i ++) {
40+ String data = br .readLine ();
41+ for (int j =0 ; j <M ; j ++) {
42+ maze [i ][j ] = data .charAt (j );
43+ if (maze [i ][j ] == CURRENT ) {
44+ x = i ;
45+ y = j ;
46+ }
47+ }
48+ }
49+ 50+ System .out .println (escape (x ,y ));
51+ }
52+ 53+ static boolean [][][] visited ;
54+ static int escape (int x , int y ){
55+ Deque <Pos > pq = new ArrayDeque <>();
56+ int [] dx = {0 ,1 ,0 ,-1 };
57+ int [] dy = {1 ,0 ,-1 ,0 };
58+ 59+ pq .offer (new Pos (x ,y ,0 ,0 ));
60+ visited [x ][y ][0 ] = true ;
61+ 62+ while (!pq .isEmpty ()) {
63+ Pos pos = pq .poll ();
64+ if (maze [pos .x ][pos .y ] == EXIT ) {
65+ return pos .distance ;
66+ }
67+ 68+ for (int d =0 ; d <4 ; d ++){
69+ int nx = pos .x + dx [d ];
70+ int ny = pos .y + dy [d ];
71+ if (stop (nx ,ny , pos .hasKey )){
72+ continue ;
73+ }
74+ 75+ int key = pos .hasKey ;
76+ if (maze [nx ][ny ] >= 'A' && maze [nx ][ny ] <= 'F' ) {
77+ if ((key & 1 <<(maze [nx ][ny ] - 'A' )) > 0 ){ //가지고 있는 키와 일치하는 경우 (A=65)
78+ visited [nx ][ny ][key ] = true ;
79+ }else {
80+ continue ;
81+ }
82+ }else if (maze [nx ][ny ] >= 'a' && maze [nx ][ny ] <= 'f' ){ //키를 주운 경우
83+ key |= 1 <<(maze [nx ][ny ] - 'a' ); //a=97
84+ visited [nx ][ny ][key ] = true ;
85+ }else {
86+ visited [nx ][ny ][key ] = true ; //'.'
87+ }
88+ 89+ pq .offer (new Pos (nx ,ny ,pos .distance +1 ,key ));
90+ }
91+ }
92+ 93+ return -1 ;
94+ }
95+ 96+ static private boolean stop (int x , int y , int hasKey ){
97+ return x < 0 || x >= N || y < 0 || y >= M || maze [x ][y ] == WALL || visited [x ][y ][hasKey ];
98+ }
99+ 100+ }
0 commit comments