Dado un número par n, encuentre el promedio de los números pares del 1 al n.
Ejemplos:
Input : 10 Output : 6 Explanation: (2 + 4 + 6 + 8 + 10 )/5 = 30/5 = 6 Input : 100 Output : 51
Método 1
Podemos calcular el promedio sumando cada número par hasta n y luego dividiendo la suma por el conteo.
C++
// Program to find average of even numbers
// till a given even number.
#include <stdio.h>
// Function to calculate the average
// of even numbers
int averageEven(int n)
{
if (n % 2 != 0) {
printf("Invalid Input");
return -1;
}
int sum = 0, count = 0;
while (n >= 2) {
// count even numbers
count++;
// store the sum of even numbers
sum += n;
n = n - 2;
}
return sum / count;
}
// driver function
int main()
{
int n = 16;
printf("%d", averageEven(n));
return 0;
}
Java
// Program to find average of even numbers
// till a given even number.
import java.io.*;
class GFG {
// Function to calculate the average
// of even numbers
static int averageEven(int n)
{
if (n % 2 != 0) {
System.out.println("Invalid Input");
return -1;
}
int sum = 0, count = 0;
while (n >= 2) {
// count even numbers
count++;
// store the sum of even numbers
sum += n;
n = n - 2;
}
return sum / count;
}
// driver function
public static void main(String args[])
{
int n = 16;
System.out.println(averageEven(n));
}
}
/*This code is contributed by Nikita Tiwari.*/
Python3
# Program to find average of
# even numbers till a given
# even number.
# Function to calculate the
# average of even numbers
def averageEven(n) :
if (n % 2 != 0) :
print("Invalid Input")
return -1
sm = 0
count = 0
while (n >= 2) :
# count even numbers
count = count + 1
# store the sum of even
# numbers
sm = sm + n
n = n - 2
return sm // count
# driver function
n = 16
print(averageEven(n))
# This code is contributed by Nikita Tiwari.
C#
// C# Program to find average
// of even numbers till a
// given even number.
using System;
class GFG {
// Function to calculate the
// average of even numbers
static int averageEven(int n)
{
if (n % 2 != 0) {
Console.Write("Invalid Input");
return -1;
}
int sum = 0, count = 0;
while (n >= 2) {
// count even numbers
count++;
// store the sum of even numbers
sum += n;
n = n - 2;
}
return sum / count;
}
// driver function
public static void Main()
{
int n = 16;
Console.Write(averageEven(n));
}
}
/*This code is contributed by vt_m.*/
PHP
<?php
// PHP Program to find average of even
// numbers till a given even number.
// Function to calculate the
// average of even numbers
function averageEven( $n)
{
if ($n % 2 != 0)
{
echo("Invalid Input");
return -1;
}
$sum = 0;
$count = 0;
while ($n >= 2)
{
// count even numbers
$count++;
// store the sum of
// even numbers
$sum += $n;
$n = $n - 2;
}
return $sum / $count;
}
// Driver Code
$n = 16;
echo(averageEven($n));
//This code is contributed by vt_m.
?>
Javascript
<script>
// javascript Program to find average of even numbers
// till a given even number.
// Function to calculate the average
// of even numbers
function averageEven( n)
{
if (n % 2 != 0) {
document.write("Invalid Input");
return -1;
}
let sum = 0, count = 0;
while (n >= 2) {
// count even numbers
count++;
// store the sum of even numbers
sum += n;
n = n - 2;
}
return sum / count;
}
// driver function
let n = 16;
document.write( averageEven(n));
// This code is contributed by todaysgaurav
</script>
Producción:
9
Complejidad de tiempo: O(n)
Espacio auxiliar: O(1)
Método 2
El promedio de números pares se puede encontrar solo en pasos individuales
usando la siguiente fórmula: –
[n + 2] / 2 donde n es el último número par.
¿Cómo funciona esta fórmula?
Sabemos que hay (n)/2 números pares hasta n. Por ejemplo, hay dos números pares hasta el 4 y hay tres números pares hasta el 6.
La suma de los primeros k números pares es k * (k + 1)
Poniendo k = n/2, obtenemos la suma de los primeros n/2 números pares como n/2(n/2 + 1)
Promedio de los primeros n/2 números pares (o números pares hasta n) = (n + 2)/2
C++
// Program to find average of even numbers
// till a given even nend number.
#include <bits/stdc++.h>
using namespace std;
// Function to calculate the average
// of even numbers
int averageEven(int n)
{
if (n % 2 != 0) {
cout<<"Invalid Input";
return -1;
}
return (n + 2) / 2;
}
// driver function
int main()
{
int n = 16;
cout<<averageEven(n)<<endl;
return 0;
}
// This code is contributed by noob2000.
C
// Program to find average of even numbers
// till a given even number.
#include <stdio.h>
// Function to calculate the average
// of even numbers
int averageEven(int n)
{
if (n % 2 != 0) {
printf("Invalid Input");
return -1;
}
return (n + 2) / 2;
}
// driver function
int main()
{
int n = 16;
printf("%d", averageEven(n));
return 0;
}
Java
// Program to find average of even numbers
// till a given even number.
import java.io.*;
class GFG {
// Function to calculate the average
// of even numbers
static int averageEven(int n)
{
if (n % 2 != 0) {
System.out.println("Invalid Input");
return -1;
}
return (n + 2) / 2;
}
// driver function
public static void main(String args[])
{
int n = 16;
System.out.println(averageEven(n));
}
}
/*This code is contributed by Nikita Tiwari.*/
Python3
# Python3 program to find average of even
# numbers till a given even number.
# Function to calculate the
# average of even numbers
def averageEven(n) :
if (n % 2 != 0) :
print("Invalid Input")
return -1
return (n + 2) // 2
# Driver function
n = 16
print(averageEven(n))
# This code is contributed by Nikita Tiwari.
C#
// C# Program to find average
// of even numbers till a
// given even number.
using System;
class GFG {
// Function to calculate the
// average of even numbers
static int averageEven(int n)
{
if (n % 2 != 0) {
Console.Write("Invalid Input");
return -1;
}
return (n + 2) / 2;
}
// driver function
public static void Main()
{
int n = 16;
Console.Write(averageEven(n));
}
}
/*This code is contributed by vt_m.*/
PHP
<?php
// PHP Program to find average of even
// numbers till a given even number.
// Function to calculate the average
// of even numbers
function averageEven( $n)
{
if ($n % 2 != 0)
{
echo("Invalid Input");
return -1;
}
return ($n + 2) / 2;
}
// Driver Code
$n = 16;
echo (averageEven($n));
return 0;
// This code is contributed by vt_m.
?>
Javascript
<script>
// javascript Program to find average of even numbers
// till a given even number.
// Function to calculate the average
// of even numbers
function averageEven( n)
{
if (n % 2 != 0)
{
document.write("Invalid Input");
return -1;
}
return (n + 2) / 2;
}
// driver function
let n = 16;
document.write(averageEven(n));
// This code is contributed by Rajput-Ji
</script>
Producción :
9
Complejidad temporal: O(1) desde que se realizan operaciones constantes
Complejidad espacial: O(1) ya que usa variables constantes