[20260206] PGM / LV2 / 괄호 회전하기 / 강신지

ksinji/202602/06 PGM 괄호 회전하기.md

@@ -0,0 +1,57 @@
+```java
+import java.util.*;
+
+class Solution {
+
+    public int solution(String s) {
+        int n = s.length();
+        int answer = 0;
+
+        for (int i = 0; i < n; i++) {
+            if (valid(s, i) == true) {
+                answer++;
+            }
+        }
+
+        return answer;
+    }
+
+    private boolean valid(String s, int start) {
+        int n = s.length();
+        Deque<Character> stack = new ArrayDeque<>();
+
+        for (int k = 0; k < n; k++) {
+            char c = s.charAt((start + k) % n);
+
+            if (c == '(' || c == '[' || c == '{') {
+                stack.push(c);
+            } else {
+                if (stack.isEmpty() == true) {
+                    return false;
+                }
+
+                char top = stack.pop();
+                if (match(top, c) == false) {
+                    return false;
+                }
+            }
+        }
+
+        return stack.isEmpty();
+    }
+
+    private boolean match(char open, char close) {
+        if (open == '(' && close == ')') {
+            return true;
+        }
+        if (open == '[' && close == ']') {
+            return true;
+        }
+        if (open == '{' && close == '}') {
+            return true;
+        }
+        return false;
+    }
+}
+
+```