解法：

记录一下tle的代码

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
#define endl '\n'
bool check(vector<int>& a, int l,int k) {
	int sum = 0;
	for (int i = 0; i < a.size() && l <= a[i]; i++) {
		sum += a[i] / l;
		if (sum >= k) return true;
	}
	return false;
}
int main() {
	ios::sync_with_stdio(false);
	cin.tie(0); cout.tie(0);
	int n, k;
	cin >> n >> k;
	long long sum = 0, l;
	vector<int> vec(n, 0);
	for (int i = 0; i < n; i++) {
		cin >> vec[i];
		sum += vec[i];
	}
	l = sum / k;
	sort(vec.begin(), vec.end(),greater<int>());
	while (l>0&&!check(vec,l,k)){
		l--;
	}
	if (l == 0) {
		cout << sum -k << endl;
	}
	else {
		cout << sum - l * k << endl;
	}
	return 0;
}

解法：

可能-1太慢了，二分答案

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
#define endl '\n'
bool check(vector<int>& a, int mid, int k) {
	long long sum = 0;
	for (int i = 0; i < a.size(); i++) {
		sum += a[i] / mid;
		if (sum >= k) return true;
	}
	return false;
}
signed main() {
	ios::sync_with_stdio(false);
	cin.tie(0); cout.tie(0);
	int n, k;
	long long sum = 0;
	cin >> n >> k;
	vector<int> vec(n, 0);
	for (int i = 0; i < n; i++){
		cin >> vec[i];
		sum += vec[i];
	}
	int l = 1, r = *max_element(vec.begin(), vec.end());
	long long mid, result=0;
	while (l <= r) {
		mid = l + (r - l) / 2;
		if (check(vec, mid, k)) {
			result = mid;
			l = mid + 1;
		}
		else {
			r = mid - 1;
		}
	}
	cout << sum - result * k << endl;
	return 0;
}