二分枚举”空旷指数“， 做法与跳石头类似。
#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;
//Mystery_Sky
//
#define M 10000100
#define INF 0x7f7f7f7f
#define ll long long
ll l, r, mid;
int L, n, k;
int a[M];
inline bool check(ll ans)
{
int last = 0, cnt = 0;
for(int i = 2; i <= n; i++) {
while (a[i] - last > ans) {
cnt++;
last += ans;
}
last = a[i];
}
return cnt <= k;
}
int main() {
scanf("%d%d%d", &L, &n, &k);
a[0] = 0;
for(int i = 1; i <= n; i++) scanf("%d", &a[i]);
a[++n] = L;
sort(a, a+n+1);
l = 0, r = INF;
while(l < r) {
mid = l + (r - l) /2;
if(check(mid)) r = mid;
else l = mid + 1;
}
printf("%lld
", l);
return 0;
}