In this HackerEarth Highest average <Nissan> problem solution You are given an array A of length N. You have to choose a subset S from given array A, such that the average of S is less than K. You need to print the maximum possible length of S.


HackerEarth Highest average <Nissan> problem solution


HackerEarth Highest average Nissan problem solution.

import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.io.FilterInputStream;
import java.io.BufferedInputStream;
import java.io.InputStream;

public class Main {
    public static void main(String[] args) {
        new Thread(null, new Runnable() {
            public void run() {
                new Main().solve();
            }
        }, "1", 1 << 26).start();
    }

    void solve() {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        ScanReader in = new ScanReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Highestaverage solver = new Highestaverage();
        solver.solve(1, in, out);
        out.close();
    }

    static class Highestaverage {
        public void solve(int testNumber, ScanReader in, PrintWriter out) {
            int n = in.scanInt();
            int ar[] = new int[n];
            in.scanInt(ar, n);
            long[] prefix = new long[n + 1];
            for (int i = 1; i <= n; i++) prefix[i] += prefix[i - 1] + ar[i - 1];
            CodeHash.Radix_Sort(ar);
            int q = in.scanInt();
            while (q-- > 0) {
                long k = in.scanInt();
                int low = 1;
                int high = n;
                int index = 0;
                while (low <= high) {
                    int mid = (low + high) / 2;
                    if (prefix[mid] < k * mid) {
                        index = mid;
                        low = mid + 1;
                    } else {
                        high = mid - 1;
                    }
                }
                out.println(index);
            }
        }

    }

    static class ScanReader {
        private byte[] buf = new byte[4 * 1024];
        private int index;
        private BufferedInputStream in;
        private int total;

        public ScanReader(InputStream inputStream) {
            in = new BufferedInputStream(inputStream);
        }

        private int scan() {
            if (index >= total) {
                index = 0;
                try {
                    total = in.read(buf);
                } catch (Exception e) {
                    e.printStackTrace();
                }
                if (total <= 0) return -1;
            }
            return buf[index++];
        }

        public int scanInt() {
            int integer = 0;
            int n = scan();
            while (isWhiteSpace(n)) n = scan();
            int neg = 1;
            if (n == '-') {
                neg = -1;
                n = scan();
            }
            while (!isWhiteSpace(n)) {
                if (n >= '0' && n <= '9') {
                    integer *= 10;
                    integer += n - '0';
                    n = scan();
                }
            }
            return neg * integer;
        }

        private boolean isWhiteSpace(int n) {
            if (n == ' ' || n == '\n' || n == '\r' || n == '\t' || n == -1) return true;
            else return false;
        }

        public void scanInt(int[] A, int size) {
            for (int i = 0; i < size; i++) A[i] = scanInt();
        }

    }

    static class CodeHash {
        public static void Radix_Sort(int a[]) {

            int multiplier = 1, len = a.length, max = Integer.MIN_VALUE;
            int b[] = new int[len];
            int bucket[];
            for (int i = 0; i < len; i++) if (max < a[i]) max = a[i];
            while (max / multiplier > 0) {
                bucket = new int[10];
                for (int i = 0; i < len; i++) bucket[(a[i] / multiplier) % 10]++;
                for (int i = 1; i < 10; i++) bucket[i] += (bucket[i - 1]);
                for (int i = len - 1; i >= 0; i--) b[--bucket[(a[i] / multiplier) % 10]] = a[i];
                for (int i = 0; i < len; i++) a[i] = b[i];
                multiplier *= 10;
            }

        }

    }
}

Second solution

#include<bits/stdc++.h>
#define ll long long
using namespace std;

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int n;
    cin>>n;
    assert(n>=1 && n<=500000);
    int arr[n+1];
    arr[0]=0;
    for(int i=1;i<=n;i++) { cin>>arr[i]; assert(n>=1 && n<=1000000000); }
    sort(arr+1,arr+n+1);
    long prefix[n+1];
    prefix[0]=0;
    for(int i=1;i<=n;i++){
        prefix[i]=prefix[i-1]+arr[i];
    }
    vector<double> ar;
    for(int i=1;i<=n;i++) ar.push_back(prefix[i]/double(i));
    int q;
    cin>>q;
    assert(q>=1 && q<=500000);
    while(q--){
        long k;
        cin>>k;
        assert(k>=1 && k<=1000000000);
        int idx=lower_bound(ar.begin(),ar.end(),k)-ar.begin();
        cout<<idx<<"\n";
    }
    return 0;
}