python - 给定数组arr，长度len，求满足0<=a<=b<len时。arr[b]-arr[a]的最大值

Question

如题，求python代码一行实现

Answer 1

a = your_list

max(a[j] - a[i] for i in range(len(a)) for j in range(i, len(a)))

update

max(max(a[i:]) - a[i] for i in range(len(a)))

Answer 2

max(arr[b] - arr[a] for b in range(len) for a in range(b+1))

Oh, by the way, I am writing Python 3. If you use Python 2, it is better to use xrange instead.