Merge pull request #872 from AlgorithmWithGod/JHLEE325

[20250912] BOJ / G5 / 톱니바퀴 (2) / 이준희

Author: ShinHeeEul

JHLEE325/202509/12 BOJ G5 톱니바퀴 (2).md

@@ -0,0 +1,79 @@
+```java
+import java.io.*;
+import java.util.*;
+
+public class Main {
+
+    static List<Deque<Integer>> wheel = new ArrayList<>();
+
+    public static void main(String[] args) throws Exception {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        int t = Integer.parseInt(br.readLine());
+
+        for (int i = 0; i < t; i++) {
+            String line = br.readLine();
+            Deque<Integer> dq = new LinkedList<>();
+            for (char c : line.toCharArray()) {
+                dq.add(c - '0');
+            }
+            wheel.add(dq);
+        }
+
+        int k = Integer.parseInt(br.readLine());
+
+        for (int i = 0; i < k; i++) {
+            StringTokenizer st = new StringTokenizer(br.readLine());
+            int num = Integer.parseInt(st.nextToken()) - 1;
+            int dir = Integer.parseInt(st.nextToken());
+
+            int[] dirs = new int[t];
+            dirs[num] = dir;
+
+            for (int j = num; j > 0; j--) {
+                int left = ((LinkedList<Integer>) wheel.get(j - 1)).get(2);
+                int right = ((LinkedList<Integer>) wheel.get(j)).get(6);
+                if (left != right) {
+                    dirs[j - 1] = -dirs[j];
+                } else {
+                    break;
+                }
+            }
+
+            for (int j = num; j < t - 1; j++) {
+                int left = ((LinkedList<Integer>) wheel.get(j)).get(2);
+                int right = ((LinkedList<Integer>) wheel.get(j + 1)).get(6);
+                if (left != right) {
+                    dirs[j + 1] = -dirs[j];
+                } else {
+                    break;
+                }
+            }
+
+            for (int j = 0; j < t; j++) {
+                if (dirs[j] != 0) {
+                    rotate(j, dirs[j]);
+                }
+            }
+        }
+
+        int score = 0;
+        for (int i = 0; i < t; i++) {
+            if (wheel.get(i).peekFirst() == 1) {
+                score++;
+            }
+        }
+        System.out.println(score);
+    }
+
+    public static void rotate(int idx, int dir) {
+        if (dir == 1) {
+            int last = wheel.get(idx).pollLast();
+            wheel.get(idx).addFirst(last);
+        } else {
+            int first = wheel.get(idx).pollFirst();
+            wheel.get(idx).addLast(first);
+        }
+    }
+}
+
+```