Java - 백준 코딩테스트 1065번 [함수 - 한수]

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
 
public class Hansu {
 
    public static void main(String[] args) throws IOException {
        // 20210624 - 1065번
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        
        int N = Integer.parseInt(br.readLine());
        
        int count = 0;
        
        if (N < 100) {
            count = N;
        } else if (N < 1000) {
            count = 99;
            for (int i = 100; i <= N; i++) {
                if (((i / 100) - (i % 100) / 10) == ((i % 100) / 10 - (i % 100) % 10)) {
                    count++;
                }
            }
        } else {
            count = 144;
        }
        
        bw.write(String.valueOf(count));
        bw.close();
        br.close();
    }
}