pattern 3

public class pattern3
 {
public static void main(String[] args)
 {
int i,j,k;
for(i=1; i<5;i++)
{
System.out.print("\n");
for(j=1; j<=i; j++)
{
k=j%2;
if(k==0)
System.out.print("0");
else
System.out.print("1");

}
}
}

}
output:

1
10
101
1010