评测结果

#include<iostream>
#include<algorithm>
using namespace std;
int n, k, s[100002], l, r;
int p(int x)
{
	int t = 0, last = s[0];
	for(int i = 1; i <= n + 1; i++)
	{
		if(s[i] - last > x)
		{
			t++;
		}
		else
		{
			last = (s[i] - last) / 2;
		}
	}
	return t <= k;
}
int main()
{
	cin >> l >> n >> k;
	for(int i = 1; i <= n; i++)
	{
		cin >> s[i];
	}
	r = l;
	s[n + 1] = l, l = 0;
	while(l + 1 < r)
	{
		int mid = (l + r) / 2;
		if(p(mid))
		{
			l = mid;
		}
		else
		{
			r = mid;
		}
	}
	cout << l;
	return 0;
}