Please provide me function or any tutoraial to count the completed level of a binary tree. Ex. if a tree having 2 member in first level and 3 members in second level then the completed level is 1 because the level 2 should b 4 members to complete. Please open this url: http://en.wikipedia.org/wiki/Binary_tree The tree in this url is having 1 level completed because the 2nd level should have 4 nodes.