Codeforces round 1676(E. Eating Queries)

Just use the lower bound & check is it greater than the sum or not

Lower bound:https://www.geeksforgeeks.org/upper_bound-and-lower_bound-for-vector-in-cpp-stl/

///Bismillahir Rahmanir Rahim

///Author: Tanvir Ahmmad

///CSE,Islamic University,Bangladesh

#include<iostream>

#include<cstdio>

#include<algorithm>

#include<string>

#include<cstring>

#include<sstream>

#include<cmath>

#include<cstring>

#include<vector>

#include<queue>

#include<map>

#include<set>

#include<stack>

#include<vector>

#include<iterator>

#include <functional> ///sort(arr,arr+n,greater<int>()) for decrement of array

/*every external angle sum=360 degree

  angle find using polygon hand(n) ((n-2)*180)/n*/

///Floor[Log(b)  N] + 1 = the number of digits when any number is represented in base b

using namespace std;

typedef long long ll;

int main()

{

    ll tst,n,q,num;

    cin>>tst;

    while(tst--)

    {

        vector<ll>vec;

        cin>>n>>q;

        ll arr[n+5],sum=0;

        for(ll i=0;i<n;i++) cin>>arr[i];

        sort(arr,arr+n);

        for(ll i=n-1;i>=0;i--) sum+=arr[i],vec.push_back(sum);//cout<<arr[i]<<"   "<<sum<<endl;

        for(ll i=0;i<q;i++)

        {

            cin>>num;

            ll ans=lower_bound(vec.begin(), vec.end(), num) - vec.begin() + 1;

            if(num<=sum) cout<<ans<<endl;

            else cout<<"-1"<<endl;

        }

    }

    return 0;

}

///Alhamdulillah

 

Problem Link:https://codeforces.com/contest/1676/problem/E