1.0Camdemy1.0http://media.usc.edu.tw雜湊+遞迴: 四元樹(Quadtrees)http://media.usc.edu.tw/user/http://media.usc.edu.tw/sysdata/doc/8/85d3087899a83d06/thumb_l.jpg360640<iframe width='720' height='405' id='ccShare627' frameborder='0' src='http://media.usc.edu.tw/media/e/627' allowfullscreen></iframe>video7204051:05:52四元樹Quadtrees01Observation 1: empty + some = some02Observation 2: filled + any = filled03Observation 3: preorder of tree representation04Observation 4: 9 combinations of e, f, p05Observation 5: how to hash 9 combinations06Observation 6: how to map e, f, p07Design Issue 1: Hash to 9 combinations08Design Issue 2: Hash to 9 combinations09Design Issue 3: fill pixels010Design Issue 4: skip a subtree011Design Issue 5: scan pixels within a subtree012Coding Part 1: hash to 9 combinations013Coding Part 2: scan, skip, fill014fs1280x720720x4041280x720http://media.usc.edu.tw/sysdata/doc/8/85d3087899a83d06/thumb.jpghttp://media.usc.edu.tw/sysdata/doc/8/85d3087899a83d06/cover.jpghttp://media.usc.edu.tw/sysdata/doc/8/85d3087899a83d06/video/thumbs/storyboard.jpghttp://media.usc.edu.tw/sysdata/doc/8/85d3087899a83d061