see , we can see that first lline have 1 number, second have 2 and third have 3 .....and so on. we can observe that first number of every row is sum of first k narutal number, where k is the row number. so for k=4, n=((4+1)*4)/2=10;
so run a for loop, for(int i=1;i<num_rows;i++) { prev=((i-)*i)/2; k=((i+1)*i)/2; for(int j=k;i;k>prev;j--) { cout<<prev<<" "; } cout<<endl; } On Sun, Aug 14, 2011 at 9:43 AM, Dave <dave_and_da...@juno.com> wrote: > @Beginner: The largest number n in row r satisfies n = (r^2 + r) / 2. > So using the Quadratic Formula gives > > r = ( sqrt( 8*n + 1 ) - 1 ) / 2. > > For the row number r for any n (not necessarily the largest one in a > row), > > r = ceil( sqrt( 8*n + 1 ) - 1 ) / 2 ) > > where ceil( x ) is the smallest integer not exceeding x. > > Dave > > On Aug 13, 10:22 pm, Beginner <murugavidya1...@gmail.com> wrote: > > How to print this triangle? > > 1 > > 3 2 > > 6 5 4 > > 10 9 8 7 > > and how to find the number of rows if n is given? > > For ex if n=10 how to find num of rows=4?? > > Is it Log 10 to the base of 2!!!!!! > > -- > You received this message because you are subscribed to the Google Groups > "Algorithm Geeks" group. > To post to this group, send email to algogeeks@googlegroups.com. > To unsubscribe from this group, send email to > algogeeks+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/algogeeks?hl=en. > > -- Ankur Khurana Computer Science Netaji Subhas Institute Of Technology Delhi. -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send email to algogeeks@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.