objective c - Find total no of Close polygons iOS -

i want find total number of close shape.

in image, there 6 no of close polygons . have tried following method

    (nsinteger = 0; < [arrlinesinfo count]; i++) {                nsdictionary *dictlineinfo = [arrlinesinfo objectatindex:i];                startpoint = cgpointmake([[dictlineinfo valueforkey:@"line_start_point_x"] doublevalue], [[dictlineinfo valueforkey:@"line_start_point_y"] doublevalue]);               endpoint = cgpointmake([[dictlineinfo valueforkey:@"line_end_point_x"] doublevalue], [[dictlineinfo valueforkey:@"line_end_point_y"] doublevalue]);                [self iscircularroute:startpoint withendpoint:endpoint];             }               -(void) iscircularroute:(cgpoint) linestartpoint withendpoint:(cgpoint) lineendpoint              {                 nspredicate *pre= [nspredicate predicatewithformat:[nsstring stringwithformat:@"     (self.line_end_point_x == '%f' && self.line_end_point_y == '%f') or          (self.line_start_point_x == '%f' && self.line_start_point_y == '%f') or          (self.line_end_point_x == '%f' && self.line_end_point_y == '%f') or          (self.line_start_point_x == '%f' && self.line_start_point_y == '%f')", linestartpoint.x,          linestartpoint.y,          linestartpoint.x,         linestartpoint.y,          lineendpoint.x,          lineendpoint.y,          lineendpoint.x,          lineendpoint.y]];   nsmutablearray *arrsamepointref = [[arrlinesinfo filteredarrayusingpredicate:pre] mutablecopy];   arrsamepointref = [[arrsamepointref filteredarrayusingpredicate:[nspredicate predicatewithformat:[nsstring stringwithformat:@" (self.line_start_point_x != '%f' && self.line_start_point_y != '%f') &&          (self.line_end_point_x != '%f' && self.line_end_point_y != '%f')", linestartpoint.x         , linestartpoint.y         , lineendpoint.x         , lineendpoint.y]]] mutablecopy];//[arrsamepointref removeobject:dictlineinfo];                  if(arrsamepointref.count > 2){                    totalpolygon = totalpolygon + 1;                 }                 nslog(@"totalpolygon : ===== %tu", totalpolygon);                  (nsdictionary *dictsingleline in arrsamepointref) {                      cgpoint newstartpoint = cgpointmake([[dictsingleline valueforkey:@"line_start_point_x"] doublevalue], [[dictsingleline valueforkey:@"line_start_point_y"] doublevalue]);                     cgpoint newendpoint = cgpointmake([[dictsingleline valueforkey:@"line_end_point_x"] doublevalue], [[dictsingleline valueforkey:@"line_end_point_y"] doublevalue]);                      [self iscircularroute:newstartpoint withendpoint:newendpoint];                 }              } 

this go in infinite loop.

i have start point , end point object in array. array object below

[ { "point_start_lbl" : "a", "point_end_lbl" : "b", "line_start_point_x" : 200, "line_start_point_y" : 10, "line_end_point_x" : 100, "line_end_point_y" : 10, }, ... ]

please me. in advance.

you have closed polygon if have ordered list of edges such each edge ends on vertex next starts on , no edge repeated within list.

i'm unclear data structure might therefore:

define object, edge identifies 2 vertices.

for each vertex, create array containing every single edge touches vertex.

then, like, in swift-ish pseudocode:

var successfulpaths: [edge] = [] edge in edges {     let usededges = [edge]     attempttraversalfrom(edge.vertex1, edge.vertex2, usededges, successfulpaths)     attempttraversalfrom(edge.vertex2, edge.vertex1, usededges, successfulpaths) }  print("there \(successfulpaths.count) successful paths")  [...]  func attempttraversalfrom(startingvertex, endingvertex, usededges, successfulpaths) {     let vertexedges = endingvertex.edges     edge in (edges not in usededges) {         let newendingvertex =              (edge.vertex1 == endingvertex) ? edge.vertex2 : edge.vertex1          if newendingvertex == startingvertex {             successfulpaths.add(usededges)             return         } else {             let newusededges = useredges.additem(edge)             attempttraversalfrom(startingvertex, newendingvertex, newusededges, successfulpaths)         }     }      // note: automatically fall through here , return     // without adding `successfulpaths` if there     // no further traversable edges } 

extemporaneous, etc. bit recursive part of dijkstra's pathfinding algorithm, except potential paths accumulated rather shorter paths eliminating longer ones prior complete evaluation.