Program to display binary equivalent of a number n.

import java.lang.Math;
import java.util.Scanner;

public class bi
{
public static void main(String a[]){
int number;
Scanner input=new Scanner(System.in);
int binary[] = new int[64];
int index = 0;
System.out.print("Enter number : ");
number=input.nextInt();
if(number>0)
{      
System.out.print("\nBinary = ");
while(number > 0)
{
binary[index++] = number%2;
number = number/2;
}
for(int i = index-1;i >= 0;i--)
{
System.out.print(binary[i]);
}
}
else
{
number=-number;
while(number > 0)
{
binary[index++] = number%2;
number = number/2;
}
index++;
binary[index]=0;
for(int i = index-1;i >= 0;i--)
{
if(binary[i]==1)
{
binary[i]=0;
}
else
{
binary[i]=1;
}
}
if(binary[0]==0)
binary[0]=1;
else
{
for(int i = index-1;i >= 0;i--)
{
if(binary[i]==1)
{
binary[i]=0;

}
else
{
break;

}
}
}
System.out.print("\nBinary : ");
for(int i = index-1;i >= 0;i--)
{
System.out.print(binary[i]);
}

for(int i=0;i<index;i++)
{
if(binary[i]!=0)
binary[i]=(int)Math.pow(2,i);
}
int sum=0;
for(int i=0;i<index;i++)
{
sum+=binary[i];
}
System.out.println("\nDecimal equivalent = "+sum);
}


System.out.println();
}
}