EVIL NUMBER:
In number theory, an evil number is a non-negative number that has an even number of 1s in its binary expansion.
In number theory, an evil number is a non-negative number that has an even number of 1s in its binary expansion.
The first evil numbers are:
- 0, 3, 5, 6, 9, 10, 12, 15, 17, 18, 20, 23, 24, 27, 29, 30, 33, 34, 36, 39 .
These numbers give the positions of the zero values in the Thue–Morse sequence.
Numbers that are not evil are called odious numbers.
/* program to check given number is evil number or not*/
import java.io.*;
public class EvilNumber
{
public static void main(String args[])throws IOException
{
int num, a, count , c, i;
int binNum[] = new int[20];
InputStreamReader in = new InputStreamReader(System.in);
BufferedReader br = new BufferedReader(in);
System.out.println("Enter a number:");
num = Integer.parseInt(br.readLine());
count = 0; // count the number of 1's
c = 0; // for index of array
while(num!=0)
{
a = num % 2;
binNum[c] = a;
if(a == 1)
count++;
num = num / 2;
c++;
}
System.out.println("Total number of 1 is = " + count);
// Print the binary number
for(i=c-1; i>=0 ; i--)
{
System.out.print(binNum[i]+" ");
}
// Checking the number is Evil or Not
if(count % 2 == 0)
{
System.out.println("\nEntered number is Evil an Number");
}
else
{
System.out.println("\nEntered number is not an Evil Number");
}
}
}
OUTPUT:
Enter a number:
10
Total number of 1 is = 2
1 0 1 0
Entered number is Evil an Number
Enter a number:
13
Total number of 1 is = 3
1 1 0 1
Entered number is not an Evil Number
