求助

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N=1e7+10;
ll n,m,a[N],ans;
bool check(ll x)
{
	ll ans=0;
	for(int i=1;i<=m;i++) ans+=(a[i]+x-1)/x;
	return ans<=n;
}
int main()
{
	cin>>n>>m;
	ll sum=0;
	ll l=1,mid;
	for(int i=1;i<=n;i++)
		cin>>a[i],sum+=a[i];
	while(l<=sum)
	{
		mid=(l+sum)/2;
		if(check(mid))
			ans=mid,sum=mid-1;
		else
			l=mid+1;
	}
	cout<<ans;
	return 0;
}