Maximum count of equal numbers in an array after performing given operations

Given an array of integers. The task is to find the maximum count of equal numbers in an array after applying the given operation any number of times. 
In an operation: 

1. Choose two elements of the array a[i], a[j] (such that i is not equals to j) and, 
2. Increase number a[i] by 1 and decrease number a[j] by 1 i.e., a[i] = a[i] + 1 and a[j] = a[j] – 1. 

Examples: 

Input: a = { 1, 4, 1 }
Output: 3
after first step { 1, 3, 2}
after second step { 2, 2, 2}

Input: a = { 1, 2 }
Output: 1

Approach :

1. Calculate the sum of the array elements.
2. If the sum is divisible by n, where n is the number of elements in the array then the answer will also be n.
3. Otherwise, the answer will be n-1.

Below is the implementation of the above approach:  

C++

// CPP program to find the maximum
// number of equal numbers in an array

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

// Function to find the maximum number of
// equal numbers in an array
int EqualNumbers(int a[], int n)
{
    // to store sum of elements
    int sum = 0;
    for (int i = 0; i < n; i++)
        sum += a[i];

    // if sum of numbers is not divisible
    // by n
    if (sum % n)
        return n - 1;

    return n;
}

// Driver Code
int main()
{
    int a[] = { 1, 4, 1 };

    // size of an array
    int n = sizeof(a) / sizeof(a[0]);

    cout << EqualNumbers(a, n);

    return 0;
}

C

//C program to find the maximum
// number of equal numbers in an array
#include <stdio.h>

// Function to find the maximum number of
// equal numbers in an array
int EqualNumbers(int a[], int n)
{
  // storing the sum of elements
  int sum = 0;
  for (int i = 0; i < n; i++)
    sum += a[i];

  // checking if sum of numbers is not divisible
  // by n
  if (sum % n)
    return n - 1;

  return n;
}

// Driver Code
int main()
{
  int a[] = { 1, 4, 1 };

  // Size of the array
  int n = sizeof(a) / sizeof(a[0]);

  printf("%d\n", EqualNumbers(a, n));

  return 0;
}

// This code is contributed by phalashi

Java

// Java program to find the maximum
// number of equal numbers in an array

public class GFG{

    // Function to find the maximum number of
    // equal numbers in an array
    static int EqualNumbers(int a[], int n)
    {
        // to store sum of elements
        int sum = 0;
        for (int i = 0; i < n; i++)
            sum += a[i];

        // if sum of numbers is not divisible
        // by n
        if (sum % n != 0)
            return n - 1;

        return n;
    }


    // Driver code
    public static void main(String args[])
    {
            int a[] = { 1, 4, 1 };

            // size of an array
            int n = a.length;

            System.out.println(EqualNumbers(a, n));
    }
    // This code is contributed by ANKITRAI1
}

Python3

# Python3 program to find the maximum
# number of equal numbers in an array

# Function to find the maximum
# number of equal numbers in an array
def EqualNumbers(a, n):

    # to store sum of elements
    sum = 0;
    for i in range(n):
        sum += a[i];

    # if sum of numbers is not
    # divisible by n
    if (sum % n):
        return n - 1;

    return n;

# Driver Code
a = [1, 4, 1 ];

# size of an array
n = len(a);

print(EqualNumbers(a, n));

# This code is contributed by mits

C#

// C# program to find the maximum
// number of equal numbers in an array
using System;

class GFG
{
// Function to find the maximum
// number of equal numbers in an array
static int EqualNumbers(int []a, int n)
{
    // to store sum of elements
    int sum = 0;
    for (int i = 0; i < n; i++)
        sum += a[i];

    // if sum of numbers is not
    // divisible by n
    if (sum % n != 0)
        return n - 1;

    return n;
}

// Driver code
static public void Main ()
{
    int []a = { 1, 4, 1 };

    // size of an array
    int n = a.Length;

    Console.WriteLine(EqualNumbers(a, n));
}
}

// This code is contributed by jit_t

PHP

<?php
// PHP program to find the maximum
// number of equal numbers in an array

// Function to find the maximum
// number of equal numbers in an array
function EqualNumbers($a, $n)
{
    // to store sum of elements
    $sum = 0;
    for ($i = 0; $i < $n; $i++)
        $sum += $a[$i];

    // if sum of numbers is not
    // divisible by n
    if ($sum % $n)
        return $n - 1;

    return $n;
}

// Driver Code
$a = array(1, 4, 1 );

// size of an array
$n = sizeof($a);

echo EqualNumbers($a, $n);

// This code is contributed
// by Akanksha Rai

Javascript

<script>

// JavaScript program to find the maximum
// number of equal numbers in an array

// Function to find the maximum number of
// equal numbers in an array
function EqualNumbers(a, n)
{
    // to store sum of elements
    let sum = 0;
    for (let i = 0; i < n; i++)
        sum += a[i];

    // if sum of numbers is not divisible
    // by n
    if (sum % n)
        return n - 1;

    return n;
}

// Driver Code

    let a = [ 1, 4, 1 ];

    // size of an array
    let n = a.length;

    document.write(EqualNumbers(a, n));

// This code is contributed by Surbhi Tyagi.

</script>

Output

3

Complexity Analysis:

• Time Complexity: O(n), where n represents the size of the given array.
• Auxiliary complexity: O(1), no extra space is required, so it is a constant.