问一下题呗求求了（qute）

#include<bits/stdc++.h>
using namespace std;
struct FZD{
	int lastnum;
	int nowdis;
	int nextnum;
}a[500000+2];
bool cmp(FZD a,FZD b)
{
	return a.nowdis<b.nowdis;
}
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int l,m,n;
	cin>>l>>n>>m;
	for(int i=1;i<n;i++)
	{
		a[i].lastnum=i-1;
		a[i].nextnum=i+1;
		cin>>a[i].nowdis;
		a[i].nowdis-=a[a[i].lastnum].nowdis;
	} 
	cin>>a[n].nowdis;
	a[n+1].lastnum=n;
	a[n+1].nowdis=l-a[n].nowdis;
	a[n+1].nextnum=n+2;
	a[n].lastnum=n-1;
	a[n].nextnum=n+1;
	a[n].nowdis-=a[a[n].lastnum].nowdis;
	sort(a+1,a+2+n,cmp);
	for(int i=1;i<=m;i++)
	{
		a[a[i].nextnum].nowdis=a[i].nowdis+a[a[i].lastnum].nowdis;
		a[i].nowdis=0x3f3f3f3f3f;
	}
	sort(a+1,a+2+n,cmp);
	cout<<a[1].nowdis-1;
	return 0; 
}