[20250926] PGM / LV2 / 전력망을 둘로 나누기 / 김수연

[20250926] PGM / LV2 / 전력망을 둘로 나누기 / 김수연

Author: suyeun84

suyeun84/202509/26 PGM LV2 전력망을 둘로 나누기.md

@@ -0,0 +1,40 @@
+```java
+import java.util.*;
+class Solution {
+    static int N;
+    static List<List<Integer>> graph;
+    public int solution(int n, int[][] wires) {
+        int answer = Integer.MAX_VALUE;
+        N = n;
+        graph = new ArrayList<>();
+        for (int i = 0; i <= n; i++) graph.add(new ArrayList<>());
+        for (int i = 0; i < n-1; i++) {
+            graph.get(wires[i][0]).add(wires[i][1]);
+            graph.get(wires[i][1]).add(wires[i][0]);
+        }
+        for (int i = 0; i < n-1; i++) {
+            answer = Math.min(answer, check(wires[i][0], wires[i][1]));
+        }
+        
+        return answer;
+    }
+    
+    private int check(int a, int b) {
+        Queue<Integer> q = new LinkedList<>();
+        boolean[] visited = new boolean[N+1];
+        int cnt = 1;
+        visited[1] = true;
+        q.add(1);
+        while(!q.isEmpty()) {
+            int curr = q.poll();
+            for (int next : graph.get(curr)) {
+                if (visited[next] || (a==curr && b==next) || (a==next && b==curr)) continue;
+                cnt++;
+                visited[next] = true;
+                q.add(next);
+            }
+        }
+        return Math.abs((N-cnt) - cnt);
+    }
+}
+```