P10450 [USACO03MAR] Best Cow Fences G

**Original problem from: USACO 2003 Mar. Green.** Given a non-negative integer sequence $A$ of length $n$, find a subarray with the maximum average value, with length at least $L$.

The first line contains two integers $n$ and $L$, separated by spaces. The second line contains $n$ non-negative integers separated by spaces, representing $A_i$.

Output one integer, which is $1000$ times this maximum average. Do not round; output it directly.

Constraints: $1 \leq n \leq 10^5,0 \leq A_i \leq 2000$。 Translated by ChatGPT 5