From 6c62b1140284c7c5175c79bc0db54f15b16caa41 Mon Sep 17 00:00:00 2001
From: lkhyun <102892446+lkhyun@users.noreply.github.com>
Date: Sun, 14 Sep 2025 22:50:50 +0900
Subject: [PATCH] =?UTF-8?q?[20250914]=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=9D=B4?=
 =?UTF-8?q?=EA=B0=95=ED=98=84?=
MIME-Version: 1.0
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---
 ...4 \352\267\270\353\236\230\355\224\204.md" | 68 +++++++++++++++++++
 1 file changed, 68 insertions(+)
 create mode 100644 "lkhyun/202509/14 BOJ G4 \354\235\264\353\266\204 \352\267\270\353\236\230\355\224\204.md"

diff --git "a/lkhyun/202509/14 BOJ G4 \354\235\264\353\266\204 \352\267\270\353\236\230\355\224\204.md" "b/lkhyun/202509/14 BOJ G4 \354\235\264\353\266\204 \352\267\270\353\236\230\355\224\204.md"
new file mode 100644
index 00000000..37fa7c08
--- /dev/null
+++ "b/lkhyun/202509/14 BOJ G4 \354\235\264\353\266\204 \352\267\270\353\236\230\355\224\204.md"	
@@ -0,0 +1,68 @@
+```java
+import java.io.*;
+import java.util.*;
+
+public class Main {
+    static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+    static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+    static StringTokenizer st;
+    static int K;
+    static int V, E;
+    static List<Integer>[] adjLists;
+
+    public static void main(String[] args) throws IOException {
+        K = Integer.parseInt(br.readLine());
+        
+        for (int i = 0; i < K; i++) {
+            st = new StringTokenizer(br.readLine());
+            V = Integer.parseInt(st.nextToken());
+            E = Integer.parseInt(st.nextToken());
+            adjLists = new List[V + 1];
+            for (int j = 1; j <= V; j++) {
+                adjLists[j] = new ArrayList<>();
+            }
+            for (int j = 0; j < E; j++) {
+                st = new StringTokenizer(br.readLine());
+                int u = Integer.parseInt(st.nextToken());
+                int v = Integer.parseInt(st.nextToken());
+                adjLists[u].add(v);
+                adjLists[v].add(u);
+            }
+            if (!BFS()) {
+                bw.write("NO\n");
+            } else {
+                bw.write("YES\n");
+            }
+        }
+        bw.close();
+    }
+
+    public static boolean BFS() {
+        ArrayDeque<Integer> q = new ArrayDeque<>();
+        int[] visited = new int[V+1];
+        
+        for (int i = 1; i <= V; i++) {
+            if (visited[i] == 0) {  
+                q.offer(i);
+                visited[i] = 1;  
+                
+                while (!q.isEmpty()) {
+                    int cur = q.poll();
+                    
+                    for (int next : adjLists[cur]) {
+                        if (visited[next] == 0) {
+                            visited[next] = -visited[cur];
+                            q.offer(next);
+                        } else if (visited[next] == visited[cur]) {
+                            
+                            return false;
+                        }
+                    }
+                }
+            }
+        }
+        return true;
+    }
+}
+
+```