UESTC 1817 Complete Building the Houses 贪心

/*
author:jxy
lang:C/C++
university:China,Xidian University
**If you need to reprint,please indicate the source**
*/
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <queue>
#define INF 1E9
using namespace std;
int a[1000001];
long long ans=0;
int main()
{
int now;
int T,C=0;
int n,m,i,t;
scanf("%d",&T);
while(T--)
{
ans=now=0;
scanf("%d%d",&n,&m);
for(i=0;i<n;i++)
{
scanf("%d",&t);
if(now>=t)
a[i]=0;
else
{
a[i]=t-now;
ans+=a[i];
now=t;
}
if(i+1-m>=0)//超过m长度
now-=a[i+1-m];
}
printf("Case #%d: %lld\n",++C,ans);
}
}