[solved] boj16120

LeeTaeHo/boj/boj16120.java

@@ -0,0 +1,37 @@
+import java.io.*;
+import java.util.*;
+
+public class boj16120 {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        char[] ppap = br.readLine().toCharArray();
+        if (isPPAP(ppap)) {
+            System.out.println("PPAP");
+        } else {
+            System.out.println("NP");
+        }
+    }
+
+    static boolean isPPAP(char[] ppap) {
+        if (ppap.length < 4) {
+            return ppap.length == 1 && ppap[0] == 'P';
+        }
+
+        Stack<Character> s = new Stack<>();
+
+        for (int i = 0; i < 3; i++) {
+            s.push(ppap[i]);
+        }
+
+        for (int i = 3; i < ppap.length; i++) {
+            if (s.size() >= 3 && ppap[i] == 'P' && s.elementAt(s.size() - 1) == 'A' && s.elementAt(s.size() - 2) == 'P' && s.elementAt(s.size() - 3) == 'P') {
+                for (int j = 0; j < 3; j++) {
+                    s.pop();
+                }
+            }
+            s.push(ppap[i]);
+        }
+
+        return s.size() == 1 && s.peek() == 'P';
+    }
+}