11053 가장 긴 증가하는 부분

import java.io.IOException;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.StringTokenizer;
public class main {
	static int[] arr;
	static int[] dp;
	static int N;
	static int count=0;
	public static void main(String[] args) throws IOException {
    
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
		
		N = Integer.parseInt(br.readLine());
		arr = new int[N+1];
		dp = new int[N+1];
		
		StringTokenizer st = new StringTokenizer(br.readLine()," ");
		for(int i=1; i<=N; i++) {
			arr[i]=Integer.parseInt(st.nextToken());
		}
		
		dp[1]=1;
		
		for(int i=2; i<=N; i++) {
			dp[i]=1;
			for(int j=1;j<i;j++) {
				if(arr[i]>arr[j]) {
					dp[i]=Math.max(dp[i],dp[j]+1);
				}
			}
		}
		
		int max=Integer.MIN_VALUE;
		for(int i=1;i<=N;i++) {
			max = Math.max(dp[i],max);
		}
		
		bw.write(max+"\n");
		bw.flush();
		bw.close();
		
    }
}

LIS라고 해서,, 그냥 바로 풀이봤다 더 완벽히 이해해볼게요,,