Distribute given arrays into K sets such that total sum of maximum and minimum elements of all sets is maximum

Last Updated : 30 Jul, 2021

Given two arrays, the first arr[] of size N and the second brr[] of size K. The task is to divide the first array arr[] into K sets such that the i-th set should contain brr[i] elements from the second array brr[], and the total sum of maximum and minimum elements of all sets is maximum.

Examples:

Input: n = 4, k = 2, arr[] = {10, 10, 11, 11 }, brr[] = {2, 2 }
Output: 42
Explanation: First set = 10 11, sum of maximum and minimum = 21, Second set = 10 11, sum of maximum and minimum = 21. Total sum = 42 (maximum possible)

Input: n = 4, k = 4, arr[] = {10, 10, 10, 10}, brr[] = {1, 1, 1, 1 }
Output: 42

Approach: Give the greatest elements to set with size =1. For the rest, sort both the arrays, arr[] in descending order and brr[] in ascending order. Now, if the size of the set is not 1, then add the minimum element to the answer. Follow the steps below to solve the problem:

Sort the arrays, arr[] in descending order and brr[] in ascending order.
Initialize the variable say ans as 0 to store the value of the answer and cnt as 0 to count the number of sets with size 1.
Iterate in a range [0, K] and count the number of sets at size 1 and store the value in the variable cnt.
Iterate in a range [0, K] and perform the following steps.
- Add the value of arr[i] to the variable ans as the value arr[i] will be the maximum value for the i-th set.
- If the value of cnt is greater than 0, then, add the value arr[i] again as it will be minimum value also and subtract the value of cnt by 1.
Initialize the variable from as K to maintain the counter.
Iterate in a range [0, K] and perform the following steps.
- If the value of brr[i] is 1, then, continue.
- Add the value of arr[from + brr[i] – 2] to the answer.
- Increase the value of from by brr[i]-1.
Print the final value of answer.

Below is the implementation of the above approach.

C++

// C++ program for the above approach
#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
 
// Function to find K sets such that the
// sum of maximum and minimum of all sets
// is maximum
void findSets(int n, int k, vector<int>& arr,
              vector<int>& brr)
{
    ll ans = 0;
 
    // Sort both the arrays
    // arr[] in descending order.
    // brr[] in ascending order.
    sort(arr.begin(), arr.end());
    sort(brr.begin(), brr.end());
    reverse(arr.begin(), arr.end());
 
    int cnt = 0;
 
    // Count the number of sets with size 1
    for (int& v : brr) {
        if (v == 1)
            cnt++;
    }
 
    // Assign the first K maximum elements
    // to the sets and add them as minimum
    // also for sets with size 1.
    for (int i = 0; i < k; i++) {
        ans += arr[i];
        if (cnt > 0) {
            ans += arr[i];
            cnt--;
        }
    }
 
    int from = k;
    // Add the minimum element from the set.
    for (int i = 0; i < k; i++) {
        if (brr[i] == 1)
            continue;
        ans += arr[from + brr[i] - 2];
        from += brr[i] - 1;
    }
 
    cout << ans << '\n';
}
 
// Driver Code
int main()
{
    int n, k;
 
    n = 4;
    k = 2;
 
    vector<int> arr{ 10, 10, 11, 11 };
    vector<int> brr{ 2, 2 };
 
    findSets(n, k, arr, brr);
 
    return 0;
}

Java

import java.util.Arrays;
import java.util.Collections;
 
// C++ program for the above approach
class GFG {
 
    // Function to find K sets such that the
    // sum of maximum and minimum of all sets
    // is maximum
    public static void findSets(int n, int k, int[] arr, int[] brr) {
        int ans = 0;
 
        // Sort both the arrays
        // arr[] in descending order.
        // brr[] in ascending order.
        Arrays.sort(arr);
        Arrays.sort(brr);
 
        Collections.reverse(Arrays.asList(arr));
 
        int cnt = 0;
 
        // Count the number of sets with size 1
        for (int v : brr) {
            if (v == 1)
                cnt++;
        }
 
        // Assign the first K maximum elements
        // to the sets and add them as minimum
        // also for sets with size 1.
        for (int i = 0; i < k; i++) {
            ans += arr[i];
            if (cnt > 0) {
                ans += arr[i];
                cnt--;
            }
        }
 
        int from = k;
        // Add the minimum element from the set.
        for (int i = 0; i < k; i++) {
            if (brr[i] == 1)
                continue;
            ans += arr[from + brr[i] - 2];
            from += brr[i] - 1;
        }
 
        System.out.println(ans);
    }
 
    // Driver Code
    public static void main(String args[]) {
        int n, k;
 
        n = 4;
        k = 2;
 
        int[] arr = { 10, 10, 11, 11 };
        int[] brr = { 2, 2 };
 
        findSets(n, k, arr, brr);
 
    }
 
}
 
// This code is contributed by gfgking.

Python3

# python 3 program for the above approach
# Function to find K sets such that the
# sum of maximum and minimum of all sets
# is maximum
def findSets(n, k, arr, brr):
    ans = 0
 
    # Sort both the arrays
    # arr[] in descending order.
    # brr[] in ascending order.
    arr.sort()
    brr.sort()
    arr = arr[:-1]
 
    cnt = 0
 
    # Count the number of sets with size 1
    for v in brr:
        if (v == 1):
            cnt += 1
 
    # Assign the first K maximum elements
    # to the sets and add them as minimum
    # also for sets with size 1.
    for i in range(k):
        ans += arr[i]
        if (cnt > 0):
            ans += arr[i]
            cnt -= 1
 
    from1 = k
    # Add the minimum element from the set.
    for i in range(k):
        if (brr[i] == 1):
            continue
        if from1 + brr[i] - 2>len(arr)-1:
            continue;
        ans += arr[from1 + brr[i] - 2]
        from1 += brr[i] - 1
 
    print(ans)
 
# Driver Code
if __name__ == '__main__':
    n = 4
    k = 2
 
    arr =  [10, 10, 11, 11]
    brr =  [2, 2]
    findSets(n, k, arr, brr)

C#

// C# program for the above approach
using System;
using System.Collections.Generic;
 
class GFG{
 
// Function to find K sets such that the
// sum of maximum and minimum of all sets
// is maximum
static void findSets(int n, int k, List<int> arr,
              List<int> brr)
{
    int ans = 0;
 
    // Sort both the arrays
    // arr[] in descending order.
    // brr[] in ascending order.
    arr.Sort();
    brr.Sort();
    arr.Reverse();
 
    int cnt = 0;
 
    // Count the number of sets with size 1
    foreach (int v in brr) {
        if (v == 1)
            cnt++;
    }
 
    // Assign the first K maximum elements
    // to the sets and add them as minimum
    // also for sets with size 1.
    for (int i = 0; i < k; i++) {
        ans += arr[i];
        if (cnt > 0) {
            ans += arr[i];
            cnt--;
        }
    }
 
    int from = k;
    // Add the minimum element from the set.
    for (int i = 0; i < k; i++) {
        if (brr[i] == 1)
            continue;
        ans += arr[from + brr[i] - 2];
        from += brr[i] - 1;
    }
 
    Console.Write(ans);
}
 
// Driver Code
public static void Main()
{
    int n, k;
 
    n = 4;
    k = 2;
 
    List<int> arr = new List<int>(){ 10, 10, 11, 11 };
    List<int> brr = new List<int>(){ 2, 2 };
 
    findSets(n, k, arr, brr);
}
}
 
// This code is contributed by SURENDRA_GANGWAR.

Javascript

<script>
 
        // JavaScript program for the above approach
 
        // Function to find K sets such that the
        // sum of maximum and minimum of all sets
        // is maximum
        function findSets(n, k, arr, brr)
        {
            let ans = 0;
 
            // Sort both the arrays
            // arr[] in descending order.
            // brr[] in ascending order.
            arr.sort((a, b) => a - b);
            brr.sort((a, b) => a - b);
 
            arr.reverse();
 
            let cnt = 0;
 
            // Count the number of sets with size 1
            for (let v of brr) {
                if (v == 1)
                    cnt++;
            }
 
            // Assign the first K maximum elements
            // to the sets and add them as minimum
            // also for sets with size 1.
            for (let i = 0; i < k; i++) {
                ans += arr[i];
                if (cnt > 0) {
                    ans += arr[i];
                    cnt--;
                }
            }
 
            let from = k;
            // Add the minimum element from the set.
            for (let i = 0; i < k; i++) {
                if (brr[i] == 1)
                    continue;
                ans += arr[from + brr[i] - 2];
                from += brr[i] - 1;
            }
 
            document.write(ans);
        }
 
        // Driver Code
        let n, k;
 
        n = 4;
        k = 2;
 
        let arr = [10, 10, 11, 11];
        let brr = [2, 2];
 
        findSets(n, k, arr, brr);
         
    // This code is contributed by Potta Lokesh
    </script>