p2678 跳石头

#include <cmath>
#include <cstring>
#include <cstdio>
using namespace std;
const int manx = 500005;
long long L,M,N;
long long arr[manx];
long long dis[manx];
bool (int x)
{
    long long now=0,last,sum,ans=0;
    for (int i = 1; i <= M;i++)
    {
        if(arr[i]-now<=x)
        {
        	ans++;
		}
		else
		{
			now=arr[i];
		}
    }
    if(ans<=N)
        return 0;
    else
        return 1;
}
int main()
{
    cin >> L >> M >> N;
    dis[M]=L;
    for (int i = 1; i <= M;i++)
    {
        cin >> arr[i];
    }
    arr[M+1]=L;
    for (int i = 2; i <= M+1;i++)
    {
        dis[i] = arr[i] - arr[i - 1];
    }
    long long l = 0, r = L;
    while(l!=r)
    {
        int mid = l + r >> 1;
        if(check(mid))
            r = mid;
        else
            l = mid + 1;
    }
    cout << l << endl;
}