Homework 6, due Wednesday, Mar 15, in discussion section.
R-7.11 [hint: see 7.12], R-7.14
C-7.4 [hint: use some tree traversal algorithm], C-7.9, C-7.26 [hint: use a stack]
R-8.8, R-8.16, R-8.17
C-8.14, C-8.17
Scoring: each "R" exercise is worth 8 points, and each "C" exercise is worth 12 points