判断某个最短的举例是否符合条件。

#include<cstdio>
 
const int N = 50010;
int l, n, m;
int line[N];
 
bool check(int x)
{
	int now = 0, cnt = 0;
	for(int i=1; i<=n; ++i)
	{
		if(line[i] - line[now] < x)
			cnt ++;
		else
			now = i;
	}
 
	return cnt <= m;
}
 
int main()
{
	scanf("%d %d %d", &l, &n, &m);
	for(int i=1; i<=n; ++i)
		scanf("%d", &line[i]);
 
	int right = l, left = 0, mid, ans;
	while(left<right)
	{
		mid = (left+right+1)/2;
		if(check(mid))
		{
			left = mid;
		}
		else
			right = mid - 1;
	}
 
	printf("%d", left);
	return 0;
}