static int count;

    public int countSubstrings(String str) {

        count = 0;
        for (int i = 0; i < str.length(); i++) {
            /**
             * Expand for the odd length palindrome string
             */
            expandPalindrome(str, i, i);
            /**
             * Expand for the even length palindrome string
             */
            expandPalindrome(str, i, i + 1);

        }
        return count;
    }

    private void expandPalindrome(String str, int i, int j) {
        while (i >= 0 && j < str.length()) {
            if (str.charAt(i) == str.charAt(j)) {
                count++;
            } else {
                break;
            }
            i--;
            j++;
        }
    }