From 19448392c565718d49076c47c31df39837584faa Mon Sep 17 00:00:00 2001
From: lkhyun <102892446+lkhyun@users.noreply.github.com>
Date: Thu, 2 Oct 2025 17:21:18 +0900
Subject: [PATCH] =?UTF-8?q?[20251002]=20PGM=20/=20Lv2=20/=20=EB=8F=84?=
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---
 ...0 \352\267\270\353\236\230\355\224\204.md" | 72 +++++++++++++++++++
 1 file changed, 72 insertions(+)
 create mode 100644 "lkhyun/202510/02 PGM Lv2 \353\217\204\353\204\233\352\263\274 \353\247\211\353\214\200 \352\267\270\353\236\230\355\224\204.md"

diff --git "a/lkhyun/202510/02 PGM Lv2 \353\217\204\353\204\233\352\263\274 \353\247\211\353\214\200 \352\267\270\353\236\230\355\224\204.md" "b/lkhyun/202510/02 PGM Lv2 \353\217\204\353\204\233\352\263\274 \353\247\211\353\214\200 \352\267\270\353\236\230\355\224\204.md"
new file mode 100644
index 00000000..3f862c9a
--- /dev/null
+++ "b/lkhyun/202510/02 PGM Lv2 \353\217\204\353\204\233\352\263\274 \353\247\211\353\214\200 \352\267\270\353\236\230\355\224\204.md"	
@@ -0,0 +1,72 @@
+```java
+import java.util.*;
+class Solution {
+    static Map<Integer,List<Integer>> adjList = new HashMap<>();
+    static Map<Integer,Boolean> visited = new HashMap<>();
+    static Set<Integer> startCandidate = new TreeSet<>();
+    static Set<Integer> noStart = new TreeSet<>();
+    static int[] answer = new int[4];
+    
+    public int[] solution(int[][] edges) {
+        
+        for(int[] edge : edges){
+            List<Integer> temp;
+            if(adjList.containsKey(edge[0])){
+                startCandidate.add(edge[0]);
+                temp = adjList.get(edge[0]);
+            }else{
+                temp = new ArrayList<>();
+            }
+            temp.add(edge[1]);
+            adjList.put(edge[0],temp);
+            visited.put(edge[0],false);
+            visited.put(edge[1],false);
+        }
+        for(int[] edge : edges){
+            if(startCandidate.contains(edge[1])){
+                noStart.add(edge[1]);
+            }
+        }
+        for(int start : startCandidate){
+            if(!noStart.contains(start)){
+                answer[0] = start;
+                break;
+            }
+        }
+        
+        for(int start : adjList.get(answer[0])){
+            BFS(start);
+        }
+        return answer;
+    }
+    public void BFS(int start){
+        ArrayDeque<Integer> q = new ArrayDeque<>();
+        q.offer(start);
+        visited.put(start,true);
+        
+        while(!q.isEmpty()){
+            int cur = q.poll();
+            if(adjList.get(cur) == null){
+                answer[2]++;
+                return;
+            }
+            for(int next : adjList.get(cur)){
+                if(adjList.get(next) == null){
+                    answer[2]++;
+                    return;
+                }
+                if(adjList.get(next).size() == 2){
+                    answer[3]++;
+                    return;
+                }
+                if(visited.get(next)){
+                    answer[1]++;
+                    return;
+                }
+                q.offer(next);
+                visited.put(next,true);
+            }
+        }
+    }
+}
+```