Fence

题意翻译

给定一个长度为$n$的序列$h$,现在,给定一个$k$,要求你在所有长度为$k$的区间中选取一个使得它的区间和尽可能小,输出这个区间的起始位置.如果有多个满足要求的区间,输出任意一个即可.

题目描述

There is a fence in front of Polycarpus's home. The fence consists of $ n $ planks of the same width which go one after another from left to right. The height of the $ i $ -th plank is $ h_{i} $ meters, distinct planks can have distinct heights. Fence for $ n=7 $ and $ h=[1,2,6,1,1,7,1] $ Polycarpus has bought a posh piano and is thinking about how to get it into the house. In order to carry out his plan, he needs to take exactly $ k $ consecutive planks from the fence. Higher planks are harder to tear off the fence, so Polycarpus wants to find such $ k $ consecutive planks that the sum of their heights is minimal possible. Write the program that finds the indexes of $ k $ consecutive planks with minimal total height. Pay attention, the fence is not around Polycarpus's home, it is in front of home (in other words, the fence isn't cyclic).

输入输出格式

输入格式

The first line of the input contains integers $ n $ and $ k $ ( $ 1<=n<=1.5·10^{5},1<=k<=n $ ) — the number of planks in the fence and the width of the hole for the piano. The second line contains the sequence of integers $ h_{1},h_{2},...,h_{n} $ ( $ 1<=h_{i}<=100 $ ), where $ h_{i} $ is the height of the $ i $ -th plank of the fence.

输出格式

Print such integer $ j $ that the sum of the heights of planks $ j $ , $ j+1 $ , ..., $ j+k-1 $ is the minimum possible. If there are multiple such $ j $ 's, print any of them.

输入输出样例

输入样例 #1

7 3
1 2 6 1 1 7 1

输出样例 #1

3

说明

In the sample, your task is to find three consecutive planks with the minimum sum of heights. In the given case three planks with indexes 3, 4 and 5 have the required attribute, their total height is 8.