Costo mínimo para hacer que todos los elementos de la array sean iguales usando operaciones dadas

Dada una array arr[] de enteros positivos y tres enteros A , R , M , donde

  • El costo de agregar 1 a un elemento de la array es A ,
  • el costo de restar 1 de un elemento de la array es R y
  • el costo de sumar 1 a un elemento y restar 1 de otro elemento simultáneamente es M .

La tarea es encontrar el costo total mínimo para hacer que todos los elementos de la array sean iguales.

Ejemplos:

Entrada: arr[] = {5, 5, 3, 6, 5}, A = 1, R = 2, M = 4 
Salida:
Explicación:  
Operación 1: Añadir dos veces al elemento 3, Array – {5, 5 , 5, 6, 5}, Costo = 2 
Operación 2: Resta una vez al elemento 6, Array – {5, 5, 5, 5, 5}, Costo = 4 
Por lo tanto, el costo mínimo es 4.

Entrada: arr[] = {5, 5, 3, 6, 5}, A = 1, R = 2, M = 2 
Salida: 3

Enfoque: La idea es:

  1. encuentre el mínimo de M y A + R ya que M puede hacer ambas operaciones simultáneamente.
  2. Luego, almacene la suma de prefijos en una array para encontrar la suma en tiempo constante.
  3. Ahora, para cada elemento, calcule el costo de hacerlo igual al elemento actual y encuentre el mínimo de ellos.
  4. La respuesta más pequeña también puede existir cuando hacemos que todos los elementos sean iguales al promedio de la array.
  5. Por lo tanto, al final también calcule el costo de hacer que todos los elementos sean iguales a la suma promedio aproximada de elementos.

A continuación se muestra la implementación del enfoque anterior:

C++

// C++ implementation to find the
// minimum cost to make all array
// elements equal
 
#include <bits/stdc++.h>
using namespace std;
 
// Function that returns the cost of
// making all elements equal to current element
int costCalculation(
    int current, int arr[],
    int n, int pref[],
    int a, int r,
    int minimum)
{
 
    // Compute the lower bound
    // of current element
    int index
        = lower_bound(
              arr, arr + n, current)
          - arr;
 
    // Calculate the requirement
    // of add operation
    int left
        = index * current - pref[index];
 
    // Calculate the requirement
    // of subtract operation
    int right
        = pref[n] - pref[index]
          - (n - index)
                * current;
 
    // Compute minimum of left and right
    int res = min(left, right);
    left -= res;
    right -= res;
 
    // Computing the total cost of add
    // and subtract operations
    int total = res * minimum;
    total += left * a;
    total += right * r;
 
    return total;
}
 
// Function that prints minimum cost
// of making all elements equal
void solve(int arr[], int n,
           int a, int r, int m)
{
    // Sort the given array
    sort(arr, arr + n);
 
    // Calculate minimum from a + r and m
    int minimum = min(a + r, m);
 
    int pref[n + 1] = { 0 };
 
    // Compute prefix sum
    // and store in pref
    // array
    for (int i = 0; i < n; i++)
        pref[i + 1] = pref[i] + arr[i];
 
    int ans = 10000;
 
    // Find the minimum cost
    // from the given elements
    for (int i = 0; i < n; i++)
        ans
            = min(
                ans,
                costCalculation(
                    arr[i], arr, n,
                    pref, a, r,
                    minimum));
 
    // Finding the minimum cost
    // from the other cases where
    // minimum cost can occur
    ans
        = min(
            ans,
            costCalculation(
                pref[n] / n, arr,
                n, pref, a,
                r, minimum));
    ans
        = min(
            ans,
            costCalculation(
                pref[n] / n + 1,
                arr, n, pref,
                a, r, minimum));
 
    // Printing the minimum cost of making
    // all elements equal
    cout << ans << "\n";
}
 
// Driver Code
int main()
{
    int arr[] = { 5, 5, 3, 6, 5 };
 
    int A = 1, R = 2, M = 4;
 
    int size = sizeof(arr) / sizeof(arr[0]);
 
    // Function Call
    solve(arr, size, A, R, M);
 
    return 0;
}

Java

// Java implementation to find the
// minimum cost to make all array
// elements equal
import java.lang.*;
import java.util.*;
 
class GFG{
 
public static int lowerBound(int[] array, int length,
                                          int value)
{
    int low = 0;
    int high = length;
     
    while (low < high)
    {
        final int mid = (low + high) / 2;
         
        // Checks if the value is less
        // than middle element of the array
        if (value <= array[mid])
        {
            high = mid;
        }
        else
        {
            low = mid + 1;
        }
    }
    return low;
}
 
// Function that returns the cost of making
// all elements equal to current element
public static int costCalculation(int current, int arr[],
                                  int n, int pref[],
                                  int a, int r,
                                  int minimum)
{
 
    // Compute the lower bound
    // of current element
    int index = lowerBound(arr, arr.length, current);
 
    // Calculate the requirement
    // of add operation
    int left = index * current - pref[index];
 
    // Calculate the requirement
    // of subtract operation
    int right = pref[n] -
                pref[index]- (n - index)* current;
 
    // Compute minimum of left and right
    int res = Math.min(left, right);
    left -= res;
    right -= res;
 
    // Computing the total cost of add
    // and subtract operations
    int total = res * minimum;
    total += left * a;
    total += right * r;
 
    return total;
}
 
// Function that prints minimum cost
// of making all elements equal
public static void solve(int arr[], int n,
                         int a, int r, int m)
{
     
    // Sort the given array
    Arrays.sort(arr);
 
    // Calculate minimum from a + r and m
    int minimum = Math.min(a + r, m);
 
    int []pref = new int [n + 1];
    Arrays.fill(pref, 0);
     
    // Compute prefix sum and
    // store in pref array
    for(int i = 0; i < n; i++)
       pref[i + 1] = pref[i] + arr[i];
 
    int ans = 10000;
 
    // Find the minimum cost
    // from the given elements
    for(int i = 0; i < n; i++)
       ans = Math.min(ans, costCalculation(arr[i], arr,
                                           n, pref,
                                           a, r, minimum));
 
    // Finding the minimum cost
    // from the other cases where
    // minimum cost can occur
    ans = Math.min(ans, costCalculation(pref[n] / n, arr,
                                        n, pref, a, r,
                                        minimum));
    ans = Math.min(ans, costCalculation(pref[n] / n + 1,
                                        arr, n, pref,
                                        a, r, minimum));
 
    // Printing the minimum cost of making
    // all elements equal
    System.out.println(ans);
}
 
// Driver Code
public static void main(String args[])
{
    int arr[] = { 5, 5, 3, 6, 5 };
    int A = 1, R = 2, M = 4;
    int size = arr.length ;
 
    // Function Call
    solve(arr, size, A, R, M);
}
}
 
// This code is contributed by SoumikMondal

Python3

# Python3 implementation to find the
# minimum cost to make all array
# elements equal
def lowerBound(array, length, value):
 
    low = 0
    high = length
     
    while (low < high):
        mid = (low + high) // 2
         
        # Checks if the value is less
        # than middle element of the array
        if (value <= array[mid]):
            high = mid
        else:
            low = mid + 1
     
    return low
 
# Function that returns the cost of making
# all elements equal to current element
def costCalculation(current, arr,
                    n, pref, a, r, minimum):
 
    # Compute the lower bound
    # of current element
    index = lowerBound(arr, len(arr), current)
 
    # Calculate the requirement
    # of add operation
    left = index * current - pref[index]
 
    # Calculate the requirement
    # of subtract operation
    right = (pref[n] - pref[index] -
            (n - index) * current)
 
    # Compute minimum of left and right
    res = min(left, right)
    left -= res
    right -= res
 
    # Computing the total cost of add
    # and subtract operations
    total = res * minimum
    total += left * a
    total += right * r
 
    return total
 
# Function that prints minimum cost
# of making all elements equal
def solve(arr, n, a, r, m):
     
    # Sort the given array
    arr.sort()
 
    # Calculate minimum from a + r and m
    minimum = min(a + r, m)
 
    pref = [0] * (n + 1)
     
    # Compute prefix sum and
    # store in pref array
    for i in range(n):
        pref[i + 1] = pref[i] + arr[i]
 
    ans = 10000
 
    # Find the minimum cost
    # from the given elements
    for i in range(n):
        ans = min(ans, costCalculation(arr[i], arr,
                                       n, pref, a,
                                       r, minimum))
 
    # Finding the minimum cost
    # from the other cases where
    # minimum cost can occur
    ans = min(ans, costCalculation(pref[n] // n,
                                   arr, n, pref,
                                   a, r, minimum))
    ans = min(ans, costCalculation(pref[n] // n + 1,
                                   arr, n, pref, a,
                                   r, minimum))
 
    # Printing the minimum cost of making
    # all elements equal
    print(ans)
 
# Driver Code
if __name__ == "__main__":
 
    arr = [ 5, 5, 3, 6, 5 ]
    A = 1
    R = 2
    M = 4
    size = len(arr)
 
    # Function call
    solve(arr, size, A, R, M)
 
# This code is contributed by chitranayal

C#

// C# implementation to find the
// minimum cost to make all array
// elements equal
using System;
 
class GFG{
 
public static int lowerBound(int[] array,
                             int length,
                             int value)
{
    int low = 0;
    int high = length;
     
    while (low < high)
    {
        int mid = (low + high) / 2;
         
        // Checks if the value is less
        // than middle element of the array
        if (value <= array[mid])
        {
            high = mid;
        }
        else
        {
            low = mid + 1;
        }
    }
    return low;
}
 
// Function that returns the cost of making
// all elements equal to current element
public static int costCalculation(int current,
                                  int []arr, int n,
                                  int []pref, int a,
                                  int r, int minimum)
{
 
    // Compute the lower bound
    // of current element
    int index = lowerBound(arr, arr.Length, current);
 
    // Calculate the requirement
    // of add operation
    int left = index * current - pref[index];
 
    // Calculate the requirement
    // of subtract operation
    int right = pref[n] - pref[index] -
                          (n - index) *
                           current;
 
    // Compute minimum of left and right
    int res = Math.Min(left, right);
    left -= res;
    right -= res;
 
    // Computing the total cost of add
    // and subtract operations
    int total = res * minimum;
    total += left * a;
    total += right * r;
 
    return total;
}
 
// Function that prints minimum cost
// of making all elements equal
public static void solve(int []arr, int n,
                         int a, int r, int m)
{
     
    // Sort the given array
    Array.Sort(arr);
 
    // Calculate minimum from a + r and m
    int minimum = Math.Min(a + r, m);
 
    int []pref = new int [n + 1];
    Array.Fill(pref, 0);
     
    // Compute prefix sum and
    // store in pref array
    for(int i = 0; i < n; i++)
        pref[i + 1] = pref[i] + arr[i];
 
    int ans = 10000;
 
    // Find the minimum cost
    // from the given elements
    for(int i = 0; i < n; i++)
        ans = Math.Min(ans, costCalculation(arr[i], arr,
                                            n, pref, a,
                                            r, minimum));
 
    // Finding the minimum cost
    // from the other cases where
    // minimum cost can occur
    ans = Math.Min(ans, costCalculation(pref[n] / n, arr,
                                        n, pref, a, r,
                                        minimum));
    ans = Math.Min(ans, costCalculation(pref[n] / n + 1,
                                        arr, n, pref,
                                        a, r, minimum));
 
    // Printing the minimum cost of making
    // all elements equal
    Console.WriteLine(ans);
}
 
// Driver Code
public static void Main(string []args)
{
    int []arr = { 5, 5, 3, 6, 5 };
    int A = 1, R = 2, M = 4;
    int size = arr.Length ;
 
    // Function Call
    solve(arr, size, A, R, M);
}
}
 
// This code is contributed by SoumikMondal

Javascript

<script>
 
// javascript implementation to find the
// minimum cost to make all array
// elements equal   
function lowerBound(array, length, value)
{
        var low = 0;
        var high = length;
 
        while (low < high)
        {
             var mid = parseInt((low + high) / 2);
 
            // Checks if the value is less
            // than middle element of the array
            if (value <= array[mid])
            {
                high = mid;
            }
            else
            {
                low = mid + 1;
            }
        }
        return low;
    }
 
    // Function that returns the cost of making
    // all elements equal to current element
    function costCalculation(current , arr , n , pref , a , r , minimum)
    {
 
        // Compute the lower bound
        // of current element
        var index = lowerBound(arr, arr.length, current);
 
        // Calculate the requirement
        // of add operation
        var left = index * current - pref[index];
 
        // Calculate the requirement
        // of subtract operation
        var right = pref[n] - pref[index] - (n - index) * current;
 
        // Compute minimum of left and right
        var res = Math.min(left, right);
        left -= res;
        right -= res;
 
        // Computing the total cost of add
        // and subtract operations
        var total = res * minimum;
        total += left * a;
        total += right * r;
 
        return total;
    }
 
    // Function that prints minimum cost
    // of making all elements equal
    function solve(arr , n , a , r , m) {
 
        // Sort the given array
        arr.sort();
 
        // Calculate minimum from a + r and m
        var minimum = Math.min(a + r, m);
 
        var pref = Array(n+1).fill(0);
 
 
        // Compute prefix sum and
        // store in pref array
        for (i = 0; i < n; i++)
            pref[i + 1] = pref[i] + arr[i];
 
        var ans = 10000;
 
        // Find the minimum cost
        // from the given elements
        for (i = 0; i < n; i++)
            ans = Math.min(ans, costCalculation(arr[i], arr, n, pref, a, r, minimum));
 
        // Finding the minimum cost
        // from the other cases where
        // minimum cost can occur
        ans = Math.min(ans, costCalculation(pref[n] / n, arr, n, pref, a, r, minimum));
        ans = Math.min(ans, costCalculation(pref[n] / n + 1, arr, n, pref, a, r, minimum));
 
        // Printing the minimum cost of making
        // all elements equal
        document.write(ans);
    }
 
    // Driver Code
        var arr = [ 5, 5, 3, 6, 5 ];
        var A = 1, R = 2, M = 4;
        var size = arr.length;
 
        // Function Call
        solve(arr, size, A, R, M);
 
// This code is contributed by Rajput-Ji.
</script>
Producción: 

4

Complejidad de tiempo: O(n log n), usado para clasificar  
Espacio auxiliar: O(n), ya que se usa espacio adicional de tamaño n para crear una array de prefijos 

Publicación traducida automáticamente

Artículo escrito por nitinkr8991 y traducido por Barcelona Geeks. The original can be accessed here. Licence: CCBY-SA

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