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/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 numberint 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 notint 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 Codeint 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. |
Java
// Java program to check if a number is// Evil number or Odious Numberclass 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 */ |
Python3
# Python program to check if a number is# Evil number or Odious number# returns number of 1s from the binary numberdef 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 notdef 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 Codenum = 32check = checkEvil(num)if check: print(num, "is Evil Number")else: print(num, "is Odious Number")# Contributed by Harshit Agrawal |
C#
// C# program to check if a number is// Evil number or Odious Numberusing 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. |
PHP
<?php// PHP program to check if// a number is Evil number // or Odious Number// returns number of 1s // from the binary numberfunction 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 $c_one;}// Check if number // is evil or notfunction checkEvil($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.?> |
Javascript
<script>// Javascript program to check if a number// is Evil number or Odious Number// Returns number of 1s from// the binary numberfunction count_one(n){ let c_one = 0; while (n != 0) { let rem = n % 10; // Counting 1s if (rem == 1) c_one = c_one + 1; n = parseInt(n / 10, 10); } return c_one;}// Check if number is evil or notfunction checkEvil(n){ let i = 0, bin = 0, n_one = 0; // Converting n to binary form while (n != 0) { // Calculating remainder let r = n % 2; // Storing the remainders in // binary form as a number bin = bin + r * (Math.pow(10, i)); n = parseInt(n / 2, 10); } // 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 codelet check, num;num = 32;check = checkEvil(num);if (check == 1) document.write(num + " is Evil Number");else document.write(num + " is Odious Number"); // This code is contributed by suresh07 </script> |
Output
32 is Odious Number
Time Complexity: O(log2n)
Auxiliary Space: O(1), As constant extra space is used.
With the use of __builtin_parity(x): This function is used to check the parity of a number. This function returns true(1) if the number has odd parity else it returns false(0) for even parity.
C++
#include <iostream>using namespace std;int main(){ int num = 5; if (__builtin_parity(num)) cout << num << " is Odious Number\n"; else cout << num << " is Evil Number\n"; return 0;} |
Java
import java.lang.*;public class Main { public static void main(String[] args) { int num = 5; if (Integer.bitCount(num) % 2 == 1) System.out.println(num + " is Odious Number"); else System.out.println(num + " is Evil Number"); }}// This code is contributed by shiv1o43g |
Python3
# Python code addition num = 5if bin(num).count('1') % 2 == 1: print(num, "is Odious Number")else: print(num, "is Evil Number")# The code is contributed by Nidhi goel. |
C#
using System;class Program { static void Main(string[] args) { int num = 5; if (Parity(num)) Console.WriteLine(num + " is Odious Number"); else Console.WriteLine(num + " is Evil Number"); } static bool Parity(int num) { int count = 0; while (num > 0) { count++; num &= num - 1; } return (count % 2 == 1); }}// This code is contributed by user_dtewbxkn77n |
Javascript
function isOdiousNumber(num) { return (num.toString(2).split('1').length - 1) % 2 !== 0;}let num = 5;if (isOdiousNumber(num)) { console.log(num + " is Odious Number");} else { console.log(num + " is Evil Number");}// This code is contributed by shivregkec |
Output
5 is Evil Number
Time Complexity: O(log2n)
Auxiliary Space: O(1)
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