动态规划+不要开辟新的dp[i]

public class Solution {
    public int maxsumofSubarray (int[] arr) {
        int max=arr[0];
        for(int i=1;i<arr.length;i++){
            arr[i]=arr[i-1]>0?arr[i]+arr[i-1]:arr[i];
            max=Math.max(max,arr[i]);
        }
        return max;
    }
}