Application of split Search Algorithm in fbreader

In fbreader, a piece of code implements the click screen and Text Selection Function.

Looking for the footprint, I found that there was a splitting search algorithm. I didn't look at it carefully, so I thought I would try to simulate it first.

The following code is available:

Import Java. util. arraylist; import Java. util. collections; import Java. util. comparator; import Java. util. iterator; public class binearysearch {class rect {intstartx; intstarty; intendx; intendy;} class point {intx; inty ;}@ suppresswarnings ("rawtypes ") class comparatorrects implements comparator {public int compare (Object arg0, object arg1) {rect rect1 = (rect) arg0; rect rect2 = (rect) arg1; If (rect2.endy> rect1.endy) {return-1;} elseif (rect2.endy = rect1.endy) {If (rect2.endx> rect1.endx) {return-1;} elseif (rect2.endx <rect1.endx) {return 1 ;} else {return 0 ;}} else {return 1 ;}} Private Static arraylist <rect> listrects = new arraylist <binearysearch. rect> (); Private Final Static intx_max = 10; // 10 rows private final static inty_max = 20; // 10 columns private final static intrect_width = 10; // width of the simulated square private final static intrect_height = 15; // height of the simulated square private final static intwordpadding = 2; // padding private final static intlinepadding = 3; // line spacing public static void main (string ARGs []) {binearysearch bsearch = new binearysearch (); bsearch. init (); system. out. println ("=========== size:" + listrects. size (); bsearch. printrectlist (); point = bsearch. new Point (); point. X = 50; point. y = 90; int matchindex = binarysearchrect (listrects, 0, listrects. size (), point); system. out. println ("============= index:" + matchindex);} @ suppresswarnings ("unchecked") Private void printrectlist () {collections. sort (listrects, new comparatorrects (); iterator <rect> iterator = listrects. iterator (); int COUNT = 0; while (iterator. hasnext () {rect = iterator. next (); system. out. println ("=" + Count + "= X1:" + rect. startx + "X2:" + rect. endx + "Y1:" + rect. starty + "Y2:" + rect. endy); count ++ ;}} private void Init () {for (INT I = 0; I <x_max; I ++) {for (Int J = 0; j <y_max; j ++) {If (j = 0) // if it is the first line {rect = new rect (); rect. startx = I * (rect_width + wordpadding); rect. endx = (I + 1) * (rect_width + wordpadding)-wordpadding; rect. starty = linepadding; rect. endy = rect_height + linepadding; listrects. add (rect);} else {rect = new rect (); rect. startx = I * (rect_width + wordpadding); rect. endx = (I + 1) * (rect_width + wordpadding)-wordpadding; rect. starty = J * (rect_height + linepadding); rect. endy = (J + 1) * rect_height + J * linepadding; listrects. add (rect );}}}} /*** improved the text location of the square where the coordinates are located ** @ Param listrects * @ Param low * @ Param high * @ Param point * @ return */static int binarysearchrect (arraylist <rect> listrects, int low, int high, point) {int mid; If (high <= low) Return-1; Mid = (low + high) >>> 1; // or Mid = low + (high-low)/2) if (listrects. get (MID ). starty> point. y) {return binarysearchrect (listrects, low, mid, point);} elseif (listrects. get (MID ). endy <point. y) {return binarysearchrect (listrects, Mid + 1, high, point);} else {// If (listrects. get (MID ). startx> point. x) {return binarysearchrect (listrects, low, mid, point);} elseif (listrects. get (MID ). endx <point. x) {return binarysearchrect (listrects, Mid + 1, high, point);} else {return mid ;}}}}

Print result:

==========size:200====0=====x1:0 x2:10 y1:3 y2:18====1=====x1:12 x2:22 y1:3 y2:18====2=====x1:24 x2:34 y1:3 y2:18====3=====x1:36 x2:46 y1:3 y2:18====4=====x1:48 x2:58 y1:3 y2:18====5=====x1:60 x2:70 y1:3 y2:18====6=====x1:72 x2:82 y1:3 y2:18====7=====x1:84 x2:94 y1:3 y2:18====8=====x1:96 x2:106 y1:3 y2:18====9=====x1:108 x2:118 y1:3 y2:18====10=====x1:0 x2:10 y1:18 y2:33====11=====x1:12 x2:22 y1:18 y2:33====12=====x1:24 x2:34 y1:18 y2:33====13=====x1:36 x2:46 y1:18 y2:33====14=====x1:48 x2:58 y1:18 y2:33====15=====x1:60 x2:70 y1:18 y2:33====16=====x1:72 x2:82 y1:18 y2:33====17=====x1:84 x2:94 y1:18 y2:33====18=====x1:96 x2:106 y1:18 y2:33====19=====x1:108 x2:118 y1:18 y2:33====20=====x1:0 x2:10 y1:36 y2:51====21=====x1:12 x2:22 y1:36 y2:51====22=====x1:24 x2:34 y1:36 y2:51====23=====x1:36 x2:46 y1:36 y2:51====24=====x1:48 x2:58 y1:36 y2:51====25=====x1:60 x2:70 y1:36 y2:51====26=====x1:72 x2:82 y1:36 y2:51====27=====x1:84 x2:94 y1:36 y2:51====28=====x1:96 x2:106 y1:36 y2:51====29=====x1:108 x2:118 y1:36 y2:51====30=====x1:0 x2:10 y1:54 y2:69====31=====x1:12 x2:22 y1:54 y2:69====32=====x1:24 x2:34 y1:54 y2:69====33=====x1:36 x2:46 y1:54 y2:69====34=====x1:48 x2:58 y1:54 y2:69====35=====x1:60 x2:70 y1:54 y2:69====36=====x1:72 x2:82 y1:54 y2:69====37=====x1:84 x2:94 y1:54 y2:69====38=====x1:96 x2:106 y1:54 y2:69====39=====x1:108 x2:118 y1:54 y2:69====40=====x1:0 x2:10 y1:72 y2:87====41=====x1:12 x2:22 y1:72 y2:87====42=====x1:24 x2:34 y1:72 y2:87====43=====x1:36 x2:46 y1:72 y2:87====44=====x1:48 x2:58 y1:72 y2:87====45=====x1:60 x2:70 y1:72 y2:87====46=====x1:72 x2:82 y1:72 y2:87====47=====x1:84 x2:94 y1:72 y2:87====48=====x1:96 x2:106 y1:72 y2:87====49=====x1:108 x2:118 y1:72 y2:87====50=====x1:0 x2:10 y1:90 y2:105====51=====x1:12 x2:22 y1:90 y2:105====52=====x1:24 x2:34 y1:90 y2:105====53=====x1:36 x2:46 y1:90 y2:105====54=====x1:48 x2:58 y1:90 y2:105====55=====x1:60 x2:70 y1:90 y2:105====56=====x1:72 x2:82 y1:90 y2:105====57=====x1:84 x2:94 y1:90 y2:105====58=====x1:96 x2:106 y1:90 y2:105====59=====x1:108 x2:118 y1:90 y2:105====60=====x1:0 x2:10 y1:108 y2:123====61=====x1:12 x2:22 y1:108 y2:123====62=====x1:24 x2:34 y1:108 y2:123====63=====x1:36 x2:46 y1:108 y2:123====64=====x1:48 x2:58 y1:108 y2:123====65=====x1:60 x2:70 y1:108 y2:123====66=====x1:72 x2:82 y1:108 y2:123====67=====x1:84 x2:94 y1:108 y2:123====68=====x1:96 x2:106 y1:108 y2:123====69=====x1:108 x2:118 y1:108 y2:123====70=====x1:0 x2:10 y1:126 y2:141====71=====x1:12 x2:22 y1:126 y2:141====72=====x1:24 x2:34 y1:126 y2:141====73=====x1:36 x2:46 y1:126 y2:141====74=====x1:48 x2:58 y1:126 y2:141====75=====x1:60 x2:70 y1:126 y2:141====76=====x1:72 x2:82 y1:126 y2:141====77=====x1:84 x2:94 y1:126 y2:141====78=====x1:96 x2:106 y1:126 y2:141====79=====x1:108 x2:118 y1:126 y2:141====80=====x1:0 x2:10 y1:144 y2:159====81=====x1:12 x2:22 y1:144 y2:159====82=====x1:24 x2:34 y1:144 y2:159====83=====x1:36 x2:46 y1:144 y2:159====84=====x1:48 x2:58 y1:144 y2:159====85=====x1:60 x2:70 y1:144 y2:159====86=====x1:72 x2:82 y1:144 y2:159====87=====x1:84 x2:94 y1:144 y2:159====88=====x1:96 x2:106 y1:144 y2:159====89=====x1:108 x2:118 y1:144 y2:159====90=====x1:0 x2:10 y1:162 y2:177====91=====x1:12 x2:22 y1:162 y2:177====92=====x1:24 x2:34 y1:162 y2:177====93=====x1:36 x2:46 y1:162 y2:177====94=====x1:48 x2:58 y1:162 y2:177====95=====x1:60 x2:70 y1:162 y2:177====96=====x1:72 x2:82 y1:162 y2:177====97=====x1:84 x2:94 y1:162 y2:177====98=====x1:96 x2:106 y1:162 y2:177====99=====x1:108 x2:118 y1:162 y2:177====100=====x1:0 x2:10 y1:180 y2:195====101=====x1:12 x2:22 y1:180 y2:195====102=====x1:24 x2:34 y1:180 y2:195====103=====x1:36 x2:46 y1:180 y2:195====104=====x1:48 x2:58 y1:180 y2:195====105=====x1:60 x2:70 y1:180 y2:195====106=====x1:72 x2:82 y1:180 y2:195====107=====x1:84 x2:94 y1:180 y2:195====108=====x1:96 x2:106 y1:180 y2:195====109=====x1:108 x2:118 y1:180 y2:195====110=====x1:0 x2:10 y1:198 y2:213====111=====x1:12 x2:22 y1:198 y2:213====112=====x1:24 x2:34 y1:198 y2:213====113=====x1:36 x2:46 y1:198 y2:213====114=====x1:48 x2:58 y1:198 y2:213====115=====x1:60 x2:70 y1:198 y2:213====116=====x1:72 x2:82 y1:198 y2:213====117=====x1:84 x2:94 y1:198 y2:213====118=====x1:96 x2:106 y1:198 y2:213====119=====x1:108 x2:118 y1:198 y2:213====120=====x1:0 x2:10 y1:216 y2:231====121=====x1:12 x2:22 y1:216 y2:231====122=====x1:24 x2:34 y1:216 y2:231====123=====x1:36 x2:46 y1:216 y2:231====124=====x1:48 x2:58 y1:216 y2:231====125=====x1:60 x2:70 y1:216 y2:231====126=====x1:72 x2:82 y1:216 y2:231====127=====x1:84 x2:94 y1:216 y2:231====128=====x1:96 x2:106 y1:216 y2:231====129=====x1:108 x2:118 y1:216 y2:231====130=====x1:0 x2:10 y1:234 y2:249====131=====x1:12 x2:22 y1:234 y2:249====132=====x1:24 x2:34 y1:234 y2:249====133=====x1:36 x2:46 y1:234 y2:249====134=====x1:48 x2:58 y1:234 y2:249====135=====x1:60 x2:70 y1:234 y2:249====136=====x1:72 x2:82 y1:234 y2:249====137=====x1:84 x2:94 y1:234 y2:249====138=====x1:96 x2:106 y1:234 y2:249====139=====x1:108 x2:118 y1:234 y2:249====140=====x1:0 x2:10 y1:252 y2:267====141=====x1:12 x2:22 y1:252 y2:267====142=====x1:24 x2:34 y1:252 y2:267====143=====x1:36 x2:46 y1:252 y2:267====144=====x1:48 x2:58 y1:252 y2:267====145=====x1:60 x2:70 y1:252 y2:267====146=====x1:72 x2:82 y1:252 y2:267====147=====x1:84 x2:94 y1:252 y2:267====148=====x1:96 x2:106 y1:252 y2:267====149=====x1:108 x2:118 y1:252 y2:267====150=====x1:0 x2:10 y1:270 y2:285====151=====x1:12 x2:22 y1:270 y2:285====152=====x1:24 x2:34 y1:270 y2:285====153=====x1:36 x2:46 y1:270 y2:285====154=====x1:48 x2:58 y1:270 y2:285====155=====x1:60 x2:70 y1:270 y2:285====156=====x1:72 x2:82 y1:270 y2:285====157=====x1:84 x2:94 y1:270 y2:285====158=====x1:96 x2:106 y1:270 y2:285====159=====x1:108 x2:118 y1:270 y2:285====160=====x1:0 x2:10 y1:288 y2:303====161=====x1:12 x2:22 y1:288 y2:303====162=====x1:24 x2:34 y1:288 y2:303====163=====x1:36 x2:46 y1:288 y2:303====164=====x1:48 x2:58 y1:288 y2:303====165=====x1:60 x2:70 y1:288 y2:303====166=====x1:72 x2:82 y1:288 y2:303====167=====x1:84 x2:94 y1:288 y2:303====168=====x1:96 x2:106 y1:288 y2:303====169=====x1:108 x2:118 y1:288 y2:303====170=====x1:0 x2:10 y1:306 y2:321====171=====x1:12 x2:22 y1:306 y2:321====172=====x1:24 x2:34 y1:306 y2:321====173=====x1:36 x2:46 y1:306 y2:321====174=====x1:48 x2:58 y1:306 y2:321====175=====x1:60 x2:70 y1:306 y2:321====176=====x1:72 x2:82 y1:306 y2:321====177=====x1:84 x2:94 y1:306 y2:321====178=====x1:96 x2:106 y1:306 y2:321====179=====x1:108 x2:118 y1:306 y2:321====180=====x1:0 x2:10 y1:324 y2:339====181=====x1:12 x2:22 y1:324 y2:339====182=====x1:24 x2:34 y1:324 y2:339====183=====x1:36 x2:46 y1:324 y2:339====184=====x1:48 x2:58 y1:324 y2:339====185=====x1:60 x2:70 y1:324 y2:339====186=====x1:72 x2:82 y1:324 y2:339====187=====x1:84 x2:94 y1:324 y2:339====188=====x1:96 x2:106 y1:324 y2:339====189=====x1:108 x2:118 y1:324 y2:339====190=====x1:0 x2:10 y1:342 y2:357====191=====x1:12 x2:22 y1:342 y2:357====192=====x1:24 x2:34 y1:342 y2:357====193=====x1:36 x2:46 y1:342 y2:357====194=====x1:48 x2:58 y1:342 y2:357====195=====x1:60 x2:70 y1:342 y2:357====196=====x1:72 x2:82 y1:342 y2:357====197=====x1:84 x2:94 y1:342 y2:357====198=====x1:96 x2:106 y1:342 y2:357====199=====x1:108 x2:118 y1:342 y2:357============index:54

Conclusion:
Coordinates: (50, 90)

====54=====x1:48 x2:58 y1:90 y2:105

It is much better than the original traversal.