For the given array of integers, count even and odd elements.
Examples:
Input: int arr[5] = {2, 3, 4, 5, 6} Output: Number of even elements = 3 Number of odd elements = 2 Input: int arr[5] = {22, 32, 42, 52, 62} Output: Number of even elements = 5 Number of odd elements = 0
Solution: We can also check if a number is odd or even
- By doing AND of 1 and that digit, if the result comes out to be 1 then the number is odd otherwise even.
- By its divisibility by 2. A number is said to be odd if it is not divisible by 2, otherwise its even.
Here, we will check if a number is odd, then we will increment the odd counter otherwise we will increment the even counter.
Below is the implementation of the above approach:
C
// C program to count number of even // and odd elements in an array #include <stdio.h> void CountingEvenOdd( int arr[], int arr_size) { int even_count = 0; int odd_count = 0; // loop to read all the values in the array for ( int i = 0; i < arr_size; i++) { // checking if a number is completely // divisible by 2 if (arr[i] & 1 == 1) odd_count++; else even_count++; } printf ( "Number of even elements = %d \nNumber of odd " "elements = %d" , even_count, odd_count); } // Driver Code int main() { int arr[] = { 2, 3, 4, 5, 6 }; int n = sizeof (arr) / sizeof (arr[0]); // Function Call CountingEvenOdd(arr, n); } |
C++
// C++ program to count number of even // and odd elements in an array #include <iostream> using namespace std; void CountingEvenOdd( int arr[], int arr_size) { int even_count = 0; int odd_count = 0; // loop to read all the values in the array for ( int i = 0; i < arr_size; i++) { // checking if a number is completely // divisible by 2 if (arr[i] & 1 == 1) odd_count++; else even_count++; } cout << "Number of even elements = " << even_count << "\nNumber of odd elements = " << odd_count; } // Driver Code int main() { int arr[] = { 2, 3, 4, 5, 6 }; int n = sizeof (arr) / sizeof (arr[0]); // Function Call CountingEvenOdd(arr, n); } |
Java
// JAVA program to count number of even // and odd elements in an array import java.io.*; class GFG { static void CountingEvenOdd( int arr[], int arr_size) { int even_count = 0 ; int odd_count = 0 ; // loop to read all the values in // the array for ( int i = 0 ; i < arr_size; i++) { // checking if a number is // completely divisible by 2 if ((arr[i] & 1 ) == 1 ) odd_count++; else even_count++; } System.out.println( "Number of even" + " elements = " + even_count + " Number of odd elements = " + odd_count); } // Driver Code public static void main(String[] args) { int arr[] = { 2 , 3 , 4 , 5 , 6 }; int n = arr.length; // Function Call CountingEvenOdd(arr, n); } } // This code is Contributed by anuj_67. |
Python3
# Python3 program to count number of # even and odd elements in an array def CountingEvenOdd(arr, arr_size): even_count = 0 odd_count = 0 # loop to read all the values # in the array for i in range (arr_size): # checking if a number is # completely divisible by 2 if (arr[i] & 1 = = 1 ): odd_count + = 1 else : even_count + = 1 print ( "Number of even elements = " , even_count) print ( "Number of odd elements = " , odd_count) # Driver Code arr = [ 2 , 3 , 4 , 5 , 6 ] n = len (arr) # Function Call CountingEvenOdd(arr, n) # This code is contributed by sahishelangia |
C#
// C# program to count number of even // and odd elements in an array using System; class GFG { static void CountingEvenOdd( int [] arr, int arr_size) { int even_count = 0; int odd_count = 0; // loop to read all the values in // the array for ( int i = 0; i < arr_size; i++) { // checking if a number is // completely divisible by 2 if ((arr[i] & 1) == 1) odd_count++; else even_count++; } Console.WriteLine( "Number of even" + " elements = " + even_count + " Number of odd elements = " + odd_count); } // Driver Code public static void Main() { int [] arr = { 2, 3, 4, 5, 6 }; int n = arr.Length; // Function Call CountingEvenOdd(arr, n); } } // This code is Contributed by anuj_67. |
PHP
<?php // PHP program to count number of even // and odd elements in an array function CountingEvenOdd( $arr , $arr_size ) { $even_count = 0; $odd_count = 0; // loop to read all the values in // the array for ( $i = 0 ; $i < $arr_size ; $i ++) { // checking if a number is // completely divisible by 2 if ( $arr [ $i ] & 1 == 1) $odd_count ++ ; else $even_count ++ ; } echo "Number of even elements = " , $even_count , " Number of odd " , "elements = " , $odd_count ; } // Driver Code $arr = array (2, 3, 4, 5, 6); $n = count ( $arr ); // Function Call CountingEvenOdd( $arr , $n ); // This code is Contributed by anuj_67. ?> |
Javascript
<script> // Javascript program to count number of even // and odd elements in an array function CountingEvenOdd(arr, arr_size) { let even_count = 0; let odd_count = 0; // loop to read all the values in the array for (let i = 0; i < arr_size; i++) { // checking if a number is completely // divisible by 2 if (arr[i] & 1 == 1) odd_count++; else even_count++; } document.write( "Number of even elements = " + even_count + "<br>" + "Number of odd elements = " + odd_count); } // Driver Code let arr = [ 2, 3, 4, 5, 6 ]; let n = arr.length; // Function Call CountingEvenOdd(arr, n); // This code is contributed by Mayank Tyagi </script> |
Number of even elements = 3 Number of odd elements = 2
Time Complexity: O(n)
Auxiliary Space: O(1) because it is using constant space for variables
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