Problem:
Score : 200 points

Problem Statement

Find the number of palindromic numbers among the integers between A and B (inclusive).
Here, a palindromic number is a positive integer whose string representation in base 10 (without leading zeros) reads the same forward and backward.

Constraints

10000 \leq A \leq B \leq 99999

All input values are integers.

Input

Input is given from Standard Input in the following format:

A B

Output

Print the number of palindromic numbers among the integers between A and B (inclusive).

Sample Input 1

11009 11332

Sample Output 1

4

There are four integers that satisfy the conditions: 11011, 11111, 11211 and 11311.

Sample Input 2

31415 92653

Sample Output 2

612

Solution in Java (OpenJDK 11.0.6) (judge verdict: Accepted)

import java.util.Scanner;
import java.util.stream.IntStream;

public class Main {

	/** 最大値 */
	private static final int MAX = 100_000;

	public static void main(String[] args) {
		try (Scanner scanner = new Scanner(System.in)) {
			int[] count = new int[MAX];
			count[0] = 0;
			IntStream.range(1, MAX).forEach(i -> count[i] = count[i - 1] + (isPalindromic(i) ? 1 : 0));
			int a = scanner.nextInt(), b = scanner.nextInt();
			System.out.println(count[b] - count[a - 1]);
		}
	}

	/**
	 * 入力数字の10進数表現は回文かどうかを計算
	 * 
	 * @param n 入力数字
	 * @return 入力数字の10進数表現は回文かどうか
	 */
	private static boolean isPalindromic(int n) {
		char[] s = String.valueOf(n).toCharArray();
		for (int i = 0; i < s.length / 2; i++) {
			if (s[i] != s[s.length - 1 - i]) {
				return false;
			}
		}
		return true;
	}
}