Najdolga opagjacka sekvenca AIPS

import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Scanner;


public class LDS {


    private static int najdolgaOpagackaSekvenca(int[] a) {

        int []prethodnici = new int[a.length];

        for ( int i=0; i<a.length; i++ )
            prethodnici[i] = 0;


        for ( int i=0; i<a.length; i++ ){
            for ( int j = 0; j<i; j++ ){

                if ( prethodnici[i] <= prethodnici[j]&&a[i]<a[j] )
                     prethodnici[i] = prethodnici[j] + 1;
            }
        }

        int largest = 0;
        for ( int i=0; i<a.length; i++ ) {
            if (prethodnici[i] > prethodnici[largest])
                largest = i;
        }

        return prethodnici[largest] + 1;

    }



    public static void main(String[] args) {
        Scanner stdin = new Scanner(System.in);

        int n = stdin.nextInt();
        int a[] = new int[n];
        for (int i = 0; i < a.length; i++) {
            a[i] = stdin.nextInt();
        }
        System.out.println(najdolgaOpagackaSekvenca(a));
    }


}