Write a program that prompts the user to enter a positive integer N and
prints the set of all binary ({0,1}-valued) strings. For example, if the user enters 3, the program prints
000 001 010 011 100 101 110 111
and if the user enters 4, the program prints
Note: The order of these strings does not matter as long as you print all of them.
0000 0001 0010 0011 0100 0101 0110 0111 1000 1001 1010 1011 1100 1101 1110 1111