参考：https://www.luogu.com.cn/blog/leleleeee/solution-cf1003d

https://blog.csdn.net/sinat_37158899/article/details/80969585

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
int n,q,b;
int temp;
map<int,int>mp;
int main()
    {
        cin>>n>>q;
        for(int i=0;i<n;i++)
            {
                cin>>temp;
                mp[temp]++;
            }
        map<int,int>::iterator it;
        for(int i=1;i<=q;i++)
            {
                int ans=0;
                cin>>b;
                it=mp.end();
                while(1)
                    {
                        it--;
                        int minn=min(b/(it->first),it->second);
                        b-=minn*(it->first);
                        ans+=minn;
                        if(it==mp.begin()&&b!=0)
                            {
                                cout<<"-1"<<endl;
                                break;
                            }
                        else if(b==0)
                            {
                                cout<<ans<<endl;
                                break;
                            }
                        }
                }
                return 0;
            }

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