list nodes are as 6 5 4 3 2 1
push ( & head , 1 ) ; push ( & head , 2 ) ; push ( & head , 3 ) ; push ( & head , 4 ) ; push ( & head , 5 ) ; push ( & head , 6 ) ; printf ( " Given ▁ linked ▁ list : STRNEWLINE " ) ;