Submission #1024822

#	Time	Username	Problem	Language	Result	Execution time	Memory
1024822		vjudge1	Fountain (eJOI20_fountain)	C++14	60 / 100	248 ms	3156 KiB

fountain

#include <bits/stdc++.h>

using namespace std;

int main()
{
    long long n,q;
    cin>>n>>q;
    pair<long long,long long> niza[n];
    for(long long i=0; i<n; i++)cin>>niza[i].first>>niza[i].second;
    if(n<=2000 && q<=2000)
    {
        for(long long i=0; i<q; i++)
        {
            long long r,v;
            cin>>r>>v;
            r--;
            v-=niza[r].second;
            if(v<=0)
            {
                cout<<r+1<<endl;
                continue;
            }
            long long last=niza[r].first;
            r++;
            while(v>0)
            {
                if(niza[r].first>last)
                {
                    v-=niza[r].second;
                    last=niza[r].first;
                    if(v<=0)break;
                }
                r++;
                if(r==n)break;
            }
            if(r>=n)
            {
                cout<<0<<endl;
            }
            else
            {
                cout<<r+1<<endl;
            }
        }
    }
    else
    {
        long long prefsum[n];
        prefsum[0]=niza[0].second;
        for(long long i=1; i<n; i++)
        {
            prefsum[i]=prefsum[i-1]+niza[i].second;
        }
        for(long long i=0; i<q; i++)
        {
            long long r,v;
            cin>>r>>v;
            r--;
            long long b=r,e=n-1;
            long long res=INT_MAX;
            while(b<=e)
            {
                long long mid=(b+e)/2;
                long long curr=prefsum[mid];
                if(r)curr-=prefsum[r-1];
                if(curr>=v)
                {
                    res=min(res,mid);
                    e=mid-1;
                }
                else b=mid+1;
            }
            if(res==INT_MAX)res=-1;
            cout<<res+1<<endl;
        }
    }
    return 0;
}

• Subtask 1: 30 / 30
• Subtask 2: 30 / 30
• Subtask 3: 0 / 40