[D4] Title: [S/W 문제해결 기본] 4일차 - 길찾기, Time: 198 ms, Memory: 35,072 KB -BaekjoonHub

Author: son7877

SWEA/D4/1219. ［S／W 문제해결 기본］ 4일차 － 길찾기/README.md

@@ -4,11 +4,11 @@
 
 ### 성능 요약
 
-메모리: 34,944 KB, 시간: 182 ms, 코드길이: 1,786 Bytes
+메모리: 35,072 KB, 시간: 198 ms, 코드길이: 2,526 Bytes
 
 ### 제출 일자
 
-2025-10-31 17:28
+2025-10-31 17:36
 
 
 

SWEA/D4/1219. ［S／W 문제해결 기본］ 4일차 － 길찾기/［S／W 문제해결 기본］ 4일차 － 길찾기.java

@@ -1,3 +1,4 @@
+
 import java.util.*;
 
 class Solution
@@ -40,11 +41,12 @@ private static int getAnswer(int [] route) {
             map.get(from).add(to);
 
         }
-        
+
         Set<Integer> visited = new HashSet<>();
-        return dfs(0, 99, map, visited) ? 1 : 0;
+        
+        return bfs(0, 99, map, visited) ? 1 : 0;
     }
-    
+
     private static boolean dfs(
             int start, int end, HashMap<Integer, List<Integer>> map, Set<Integer> visited) {
         if (start == end) {
@@ -58,7 +60,7 @@ private static boolean dfs(
         }
 
         for (int next : map.get(start)) {
-            if (!visited.contains(next)) { // 
+            if (!visited.contains(next)) { //
                 if (dfs(next, end, map, visited)) {
                     return true;
                 }
@@ -67,4 +69,33 @@ private static boolean dfs(
 
         return false;
     }
+    
+    private static boolean bfs(
+            int start, int end, HashMap<Integer, List<Integer>> map, Set<Integer> visited
+    ) {
+        Queue<Integer> queue = new LinkedList<>();
+        
+        queue.add(start);
+        
+        while(!queue.isEmpty()) {
+            int current = queue.poll();
+
+            if (current == end) {
+                return true;
+            }
+            
+            if (!map.containsKey(current)) {
+                continue;
+            }
+            
+            for (int next : map.get(current)) {
+                if (!visited.contains(next)) {
+                    queue.add(next);
+                    visited.add(next);
+                }
+            }
+        }
+        
+        return false;
+    }
 }