滴滴笔试第一题为什么80%

话不多说，先看代码，这样总是会有数组越界的bug。。咋回事，大神来看看
public class SubMax { public static void main(String[] args) {
        Scanner in = new Scanner(System.in); while (in.hasNext()) { int n = in.nextInt(); int arr[] = new int[n]; int dp[] = new int[n]; for (int i = 0; i < n; i++) {
                arr[i] = in.nextInt();
                dp[i] = arr[i];
            } for (int i = 1; i < n; i++) {
                dp[i] = Math.max(arr[i]+dp[i-1],arr[i]);
            } long max = Integer.MIN_VALUE; for (int i = 0; i < n; i++) { if (max > arr[i])
                    max = arr[i];
            } for (int i = 0; i < n; i++) { if (max < dp[i])
                    max = dp[i];
            }
            System.out.println(max);
        }
    }
}