Program to print binary right angle triangle

Binary right angle triangle consists of only 0's and 1's in alternate positions. 
Examples : 
 

Input : 4
Output :
 0 
 1 0 
 0 1 0 
 1 0 1 0

Input : 3
Output : 
 0 
 1 0 
 0 1 0 

0 
1 0 
0 1 0 
1 0 1 0 

Time complexity: O(n*n)

Auxiliary space: O(1)