Evil Number

An evil number is a non-negative number that has an even number of 1s in its binary expansion. (Binary Expansion – is representation of a number in the binary numeral system or base-2 numeral system which represents numeric values using two different symbols: typically 0 (zero) and 1 (one)).

Odious Numbers: Numbers that are not Evil are called Odious Numbers. Given a number, the task is to check if it is Evil Number or Odious Numbers.
Examples :

Input : 3
Output : Evil Number
Explanation: Binary expansion of 3 is 11,
the number of 1s in this is 2 i.e even. 

Input : 16
Output : Odious Number(not an evil number)
Explanation: Binary expansion of 16 = 10000, 
having number of 1s =1 i.e odd.

Input : 23
Output : Evil Number
Explanation: Binary expansion of 23 is 10111,
the number of 1s in this is 4 i.e even. 

C/C++

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// C/C++ program to check if a number is
// Evil number or Odious Number
#include <iostream>
using namespace std;
#include <math.h>
  
// returns number of 1s from the binary number
int count_one(int n)
{
    int c_one = 0;
    while (n != 0) {
        int rem = n % 10;
  
        // counting 1s
        if (rem == 1)
            c_one = c_one + 1;
        n = n / 10;
    }
    return c_one;
}
  
// Check if number is evil or not
int checkEvil(int n)
{
    int i = 0, bin = 0, n_one = 0;
  
    // converting n to binary form
    while (n != 0) {
        // calculating remainder
        int r = n % 2;
  
        // storing the remainders in binary
        // form as a number
        bin = bin + r * (int)(pow(10, i));
        n = n / 2;
    }
  
    // Calling the count_one function to count
    // and return number of 1s in bin
    n_one = count_one(bin);
    if (n_one % 2 == 0)
        return 1;
    else
        return 0;
}
  
// Driver Code
int main(void)
{
    int i, check, num;
    num = 32;
    check = checkEvil(num);
    if (check == 1)
        cout << num << " is Evil Number\n";
    else
        cout << num << " is Odious Number\n";
    return 0;
}
  
// This code is contributed by Nikita Tiwari.

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Java

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// Java program to check if a number is
// Evil number or Odious Number
  
class GFG {
    // returns number of 1s from the binary number
    static int count_one(int n)
    {
        int c_one = 0;
        while (n != 0) {
            int rem = n % 10;
  
            // counting 1s
            if (rem == 1)
                c_one = c_one + 1;
            n = n / 10;
        }
        return c_one;
    }
  
    // Check if number is evil or not
    static int checkEvil(int n)
    {
        int i = 0, bin = 0, n_one = 0;
  
        // converting n to binary form
        while (n != 0) {
            // calculating remainder
            int r = n % 2;
  
            // storing the remainders in binary
            // form as a number
            bin = bin + r * (int)(Math.pow(10, i));
            n = n / 2;
        }
  
        // Calling the count_one function to count
        // and return number of 1s in bin
        n_one = count_one(bin);
        if (n_one % 2 == 0)
            return 1;
        else
            return 0;
    }
  
    // Driver Code
    public static void main(String[] args)
    {
        int i, check, num;
        num = 32;
        check = checkEvil(num);
        if (check == 1)
            System.out.println(num + " is Evil Number");
        else
            System.out.println(num + " is Odious Number");
    }
}
  
/* This code is contributed by Mr. Somesh Awasthi */

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Python

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# Python program to check if a number is 
# Evil number or Odious number
  
# returns number of 1s from the binary number
def count_one(n):
    c_one = 0
    while n != 0:
        rem = n % 10
          
        # Counting 1s
        if rem == 1:
            c_one = c_one + 1
        n = n / 10
          
    return c_one
  
# Check if nnumber is evil or not
def checkEvil(n):
    i = 0
    binary = 0
      
    # Converting n to binary form
    while n != 0:
        r = n % 2
        # Calculating Remainder
        # Storing the remainders in binary
        # form as a number
        binary = binary + r*(int(10**i))
        n = n / 2
          
    # Calling the count_one function to count
    # and return number of 1s in bin
    n_one = count_one(binary)
    if n_one % 2 == 0:
        return True
    return False
      
# Driver Code
num = 32
check = checkEvil(num)
if check:
    print num, "is Evil Nummber"
else:
    print num, "is Odious Number"        
          
# Contributed by Harshit Agrawal        

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C#

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// C# program to check if a number is
// Evil number or Odious Number
using System;
  
class GFG {
  
    // Returns number of 1s from
    // the binary number
    static int count_one(int n)
    {
        int c_one = 0;
        while (n != 0) {
            int rem = n % 10;
  
            // counting 1s
            if (rem == 1)
                c_one = c_one + 1;
            n = n / 10;
        }
        return c_one;
    }
  
    // Check if number is evil or not
    static int checkEvil(int n)
    {
        int i = 0, bin = 0, n_one = 0;
  
        // converting n to binary form
        while (n != 0) {
            // calculating remainder
            int r = n % 2;
  
            // storing the remainders in
            // binary form as a number
            bin = bin + r * (int)(Math.Pow(10, i));
            n = n / 2;
        }
  
        // Calling the count_one function to count
        // and return number of 1s in bin
        n_one = count_one(bin);
        if (n_one % 2 == 0)
            return 1;
        else
            return 0;
    }
  
    // Driver Code
    public static void Main(String[] args)
    {
        int check, num;
        num = 32;
        check = checkEvil(num);
        if (check == 1)
            Console.WriteLine(num + " is Evil Number");
        else
            Console.WriteLine(num + " is Odious Number");
    }
}
  
// This code is contributed by vt_m.

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PHP

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<?php
// PHP program to check if
// a number is Evil number 
// or Odious Number
  
// returns number of 1s 
// from the binary number
function count_one($n)
{
    $c_one = 0;
    while ($n != 0) 
    {
        $rem = $n % 10;
          
        // counting 1s
        if ($rem == 1)
            $c_one = $c_one + 1;
        $n = $n / 10;
    }
    return $c_one;
}
  
// Check if number 
// is evil or not
function checkEvil($n)
{
    $i = 0; $bin = 0; $n_one = 0;
      
    // converting n 
    // to binary form
    while ($n != 0) 
    {
        // calculating remainder
        $r = $n % 2;
          
        // storing the remainders 
        // in binary form as a number
        $bin = $bin + $r * (pow(10, $i));
        $n = $n / 2;
    }
      
    // Calling the count_one
    // function to count and 
    // return number of 1s in bin
    $n_one = count_one($bin);
    if ($n_one % 2 == 0)
        return 1;
    else
        return 0;
}
  
// Driver Code
$i; $check; $num;
$num = 32;
$check = checkEvil($num);
if ($check == 1)
    echo $num, " is Evil Number\n";
else
    echo $num, " is Odious Number\n";
  
// This code is contributed by ajit.
?>

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Output :

32 is Odius Number

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Improved By : vt_m, jit_t



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