https://www.luogu.com.cn/record/164142783

代码如下:

#include <iostream>
#include <algorithm>
using namespace std;
typedef long long lld;
lld l, n, k;
lld a[10000005];

lld check(lld x){
    lld ans=0;
    for(lld i=1;i<=n;i++){
        if(a[i]-a[i-1]<=x){
            continue;
        }
        ans+=(a[i]-a[i-1])/x;
        if(a[i]-a[i-1]%x==0){
            ans--;
        }
    }
    return ans;
}

int main() {
    cin >> l >> n >> k;
    for(lld i=1;i<=n;i++){
        cin >> a[i];
    }
    long long l=1, r=0x3f3f3f3f;
    sort(a+1, a+n+1);
    while(l<=r){
        long long mid = (l+r)/2;
        if(check(mid)<=k){
            r=mid-1;
        }
        else{
            l=mid+1;
        }
    }
    cout << l << endl;
    return 0;
}