add: Palindrimic substrings

Author: Yongseok-Choi-dev

palindromic-substrings/YoungSeok-Choi.java

@@ -0,0 +1,43 @@
+// tc O(n^3)... 입력값이 조금만 켜졌으면 바로 TLE가 발생했을 것..
+class Solution {
+    public int countSubstrings(String s) {
+        int pCnt = 0;
+
+        for (int i = 1; i <= s.length(); i++) {
+            String window = s.substring(0, i);
+            String prev = window;
+
+            if (isPalindrome(window))
+                pCnt++;
+
+            for (int j = window.length(); j < s.length(); j++) {
+                prev = new StringBuilder(prev).append(s.charAt(j)).substring(1);
+                if (isPalindrome(prev)) {
+                    pCnt++;
+                }
+            }
+        }
+
+        return pCnt;
+    }
+
+    public boolean isPalindrome(String p) {
+
+        if (p.length() <= 0)
+            return false;
+
+        int start = 0;
+        int end = p.length() - 1;
+
+        while (start <= end) {
+            if (p.charAt(start) != p.charAt(end)) {
+                return false;
+            }
+
+            start++;
+            end--;
+        }
+
+        return true;
+    }
+}