solve_xsel_by_DP: code cleanup/simplification, including replacement of BIG_NUMBER with nan, and simpler indexing during dynamic programming calculation
solve_xsel_by_DP: code cleanup/simplification, including replacement of BIG_NUMBER with nan, and simpler indexing during dynamic programming calculation

git-svn-id: f77b9233e94b7dff3d0994eb9b1574a697f5627f@330 dac0a9d6-b594-0410-bd98-f2f7f028047b

hitrace/hitrace