i used the following lazy propogation to update my tree...like i wanted to get sum of [i,j]

http://ideone.com/L8GQjo

my input was n=8;all elements set to zero.'0'.

then i gave my array number 26 to update array from i=1 to i=3;[1,3]

but i am getting tree[1]=52 instead of 78....

could any one say where i am getting wrong.....

thanks in advance