二叉树叶子和结点
................\Debug
................\.....\depth.exe
................\.....\depth.ilk
................\.....\depth.obj
................\.....\depth.pch
................\.....\depth.pdb
................\.....\vc60.idb
................\.....\vc60.pdb
................\depth.cpp
................\depth.dsp
................\depth.dsw
................\depth.ncb
................\depth.opt
................\depth.plg