想知道华为笔试第三题错在哪里

import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner cn = new Scanner(System.in);
        String s = cn.nextLine();
        String[] words = s.split(", ");
        int n = words.length;
        int[] a = new int[words.length];
        for(int i = 0 ; i < n ;i++){
            a[i] = Integer.parseInt(words[i]);
            //System.out.println(a[i]);
        }
        int[] dp = new int[1000];
        dp[0] = a[0];
        int res = a[0];
        for(int j = 1 ; j < n ; j++)   {
            if( dp[j-1] < 0 )
                dp[j] = a[j] ;
            else
                dp[j] = dp[j-1] + a[j] ;
            res = Math.max(res,dp[j]);
        }
        System.out.println(res);
    }
}