The input file input.txt ...

"AAA" 16 32
"BBB" 16 56
"CCC " 80 128
"DDD" 40 192
"EEE" 56 96

(The numbering convention I used for the nodes is as follows. The root gets id 1. Every left child gets 2*parent_id and every right child gets 2*parent_id+1.
This is one possibility. You do not necessarily have to follow this.)

Output for %mktimeindex input.txt (or %java mktimeindex input.txt)

Node 1

Parent: none
Low: 0
High: 255
Lines: nil


Node 2

Parent: 1
Low: 0
High: 128
Lines: nil


Node 4

Parent: 2
Low: 0
High: 64
Lines: nil


Node 8

Parent: 4
Low: 0
High: 32
Lines: nil


Node 17

Parent: 8
Low: 16
High: 32
Lines: AAA, BBB
Node 9
Parent: 4
Low: 32
High: 64
Lines: nil


Node 18

Parent: 9
Low: 32
High: 48
Lines: BBB
Node 37
Parent: 18
Low: 40
High: 48
Lines: DDD
Node 19
Parent: 9
Low: 48
High: 64
Lines: DDD


Node 38

Parent: 19
Low: 48
High: 56
Lines: BBB


Node 39

Parent: 19
Low: 56
High: 64
Lines: EEE
Node 5
Parent: 2
Low: 64
High: 128
Lines: DDD
Node 10
Parent: 5
Low: 64
High: 96
Lines: EEE
Node 21
Parent: 10
Low: 80
High: 96
Lines: CCC


Node 11

Parent: 5
Low: 96
High: 128
Lines: CCC
Node 3
Parent: 1
Low: 128
High: 255
Lines: nil
Node 6
Parent: 3
Low: 128
High: 192
Lines: DDD


A pictorial depiction of the tree could be as follows:
(This is also a preorder traversal of the tree. I would be great if you could use indentation like this when you print the tree, as this makes the tree so much more understandable. But this is not a requirement.)
 

0-255

0-128
0-64
0-32
NIL
16-32 (AAA,BBB)
32-64
32-48 (BBB)
NIL
40-48 (DDD)
48-64 (DDD)
48-56 (BBB)
56-64 (EEE)
64-128 (DDD)
64-96 (EEE)
NIL
80-96 (CCC)
96-128 (CCC)
128-255
128-192 (DDD)
NIL