The program is to build a node tree , then print it out as follow format, can anyone give me some hints or any reference web site about doing this, thanks.
(the symbol '+' are spaces)
output :
0
++1
+++++11
++++++++111
++++++++++++1112
+++++++++++++++++11122 Mary
+++++++++++++++++11123 Jane
++++++++112
++++++++++++1121
+++++++++++++++++11211 John
+++++12
++++++++121
++++++++++++1213
+++++++++++++++++12131 Jack