From 6798673ff99305cbef1aee479e7e432d946cce8d Mon Sep 17 00:00:00 2001
From: Jinyeong Seol <wlsdud5654@gmail.com>
Date: Sun, 23 Nov 2025 22:08:33 +0900
Subject: [PATCH] =?UTF-8?q?[20251123]=20BOJ=20/=20G4=20/=20=EC=9D=B4?=
 =?UTF-8?q?=EB=B6=84=20=EA=B7=B8=EB=9E=98=ED=94=84=20/=20=EC=84=A4?=
 =?UTF-8?q?=EC=A7=84=EC=98=81?=
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---
 ...70\353\236\230\355\224\204.md\342\200\216" | 73 +++++++++++++++++++
 1 file changed, 73 insertions(+)
 create mode 100644 "Seol-JY/202511/23 BOJ G4 \354\235\264\353\266\204 \352\267\270\353\236\230\355\224\204.md\342\200\216"

diff --git "a/Seol-JY/202511/23 BOJ G4 \354\235\264\353\266\204 \352\267\270\353\236\230\355\224\204.md\342\200\216" "b/Seol-JY/202511/23 BOJ G4 \354\235\264\353\266\204 \352\267\270\353\236\230\355\224\204.md\342\200\216"
new file mode 100644
index 00000000..12f0f2ca
--- /dev/null
+++ "b/Seol-JY/202511/23 BOJ G4 \354\235\264\353\266\204 \352\267\270\353\236\230\355\224\204.md\342\200\216"	
@@ -0,0 +1,73 @@
+```java
+import java.io.*;
+import java.util.*;
+
+public class Main {
+    static ArrayList<Integer>[] graph;
+    static int[] color;
+    
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringBuilder sb = new StringBuilder();
+        
+        int K = Integer.parseInt(br.readLine());
+        
+        while(K-- > 0) {
+            StringTokenizer st = new StringTokenizer(br.readLine());
+            int V = Integer.parseInt(st.nextToken());
+            int E = Integer.parseInt(st.nextToken());
+            
+            graph = new ArrayList[V + 1];
+            color = new int[V + 1];
+            
+            for(int i = 1; i <= V; i++) {
+                graph[i] = new ArrayList<>();
+            }
+            
+            for(int i = 0; i < E; i++) {
+                st = new StringTokenizer(br.readLine());
+                int u = Integer.parseInt(st.nextToken());
+                int v = Integer.parseInt(st.nextToken());
+                graph[u].add(v);
+                graph[v].add(u);
+            }
+            
+            boolean isBipartite = true;
+            for(int i = 1; i <= V; i++) {
+                if(color[i] == 0) {
+                    if(!bfs(i)) {
+                        isBipartite = false;
+                        break;
+                    }
+                }
+            }
+            
+            sb.append(isBipartite ? "YES" : "NO").append("\n");
+        }
+        
+        System.out.print(sb);
+    }
+    
+    static boolean bfs(int start) {
+        ArrayDeque<Integer> q = new ArrayDeque<>();
+        q.offer(start);
+        color[start] = 1;
+        
+        while(!q.isEmpty()) {
+            int cur = q.poll();
+            
+            for(int next : graph[cur]) {
+                if(color[next] == 0) {
+                    color[next] = -color[cur];
+                    q.offer(next);
+                } else if(color[next] == color[cur]) {
+                    return false;
+                }
+            }
+        }
+        
+        return true;
+    }
+}
+
+```