breed [vertices vertex] globals [ highlighted-vertices ;; auxiliary variable for adding/removing edges id-highlighted ;; -||-, represents the other end of the edge FIFO ;; data structure for BFS algorithm LIFO ;; data structure for DFS algorithm ] turtles-own [ root? ;; whether the vertex is root or not ] to setup ca set highlighted-vertices 0 set id-highlighted 0 set FIFO [] set LIFO [] ask patches [set pcolor green + 2] end to go-BFS if not any? vertices [ user-message "You need first to create a graph to do this activity" stop ] if not any? turtles with [root?] [ user-message "Choose root first" stop ] reset wait delay set FIFO lput turtles with [root?] FIFO ask first FIFO [set color orange wait delay] run-BFS end ;Breadth-first search to run-BFS ask first FIFO [ foreach sort-by [[who] of ?1 < [who] of ?2] link-neighbors with [color != orange][ ask ? [ set color orange set FIFO lput ? FIFO ask first FIFO [ ask link-with ? [ set color blue set thickness 1 output-print (word ([who] of end1 + 1) " -> " ([who] of end2 + 1)) ] ] wait delay] ] ] set FIFO but-first FIFO if not empty? FIFO [run-BFS] end to go-DFS if not any? vertices [ user-message "You need first to create a graph to do this activity" stop ] if not any? turtles with [root?] [ user-message "Choose root first" stop ] reset wait delay set LIFO lput turtles with [root?] LIFO ask last LIFO [set color orange wait delay] run-DFS end ;Depth-first search to run-DFS ask last LIFO [ if not any? link-neighbors with [color != orange] [set LIFO but-last LIFO stop] let i min-one-of (link-neighbors with [color != orange]) [who] ask min-one-of (link-neighbors with [color != orange]) [who] [ set color orange set LIFO lput i LIFO ask item ((position i LIFO) - 1) LIFO [ ask link-with i [ set color blue set thickness 1 output-print (word ([who] of end1 + 1) " -> " ([who] of end2 + 1)) ] ] wait delay] ] if not empty? LIFO [run-DFS] end to reset clear-output set FIFO [] set LIFO [] set highlighted-vertices 0 set id-highlighted 0 ask links [set thickness 0 set color grey] ask turtles with [root?] [set color blue + 2] ask turtles with [root? = false] [set color yellow set size 3 set root? false] end to add-vertex if mouse-down? [ create-vertices 1 [ set shape "vertex" set size 3 set color yellow set label who + 1 set label-color white set root? false setxy mouse-xcor mouse-ycor while [mouse-down?] [ setxy mouse-xcor mouse-ycor display ] ] ] end to add-edge if count vertices < 2[ user-message "You need to have at least 2 vertices" stop ] if mouse-down? [ let candidate min-one-of turtles [distancexy mouse-xcor mouse-ycor] if [distancexy mouse-xcor mouse-ycor] of candidate < 2 [ ask candidate [ if highlighted-vertices = 0 [set id-highlighted who] if color = yellow [ set highlighted-vertices highlighted-vertices + 1 set color red if highlighted-vertices = 2 [ create-link-with turtle id-highlighted set highlighted-vertices 0 ask turtles with [color = red] [set color yellow] ] ] ] while[mouse-down?] [display] ] ] end to remove-vertex if not any? vertices [ user-message "There are no vertices" stop ] if mouse-down? [ let candidate min-one-of turtles [distancexy mouse-xcor mouse-ycor] if [distancexy mouse-xcor mouse-ycor] of candidate < 2 [ ask candidate [ set color red ifelse user-yes-or-no? "Remove this vertex?" [die] [set color yellow] ] while [mouse-down?] [ display ] ] ] end to remove-edge if not any? links [ user-message "There are no edges" stop ] if mouse-down? [ let candidate min-one-of turtles [distancexy mouse-xcor mouse-ycor] if [distancexy mouse-xcor mouse-ycor] of candidate < 2 [ ask candidate [ if highlighted-vertices = 0 [set id-highlighted who] if color = yellow [ set highlighted-vertices highlighted-vertices + 1 set color red if highlighted-vertices = 2 [ ifelse is-link? link id-highlighted who [ ifelse user-yes-or-no? "Remove this edge?" [ ask link id-highlighted who [die] set highlighted-vertices 0 ask turtles with [color = red] [set color yellow] ] [ set highlighted-vertices 0 ask turtles with [color = red] [set color yellow] stop] ] [ set highlighted-vertices 0 ask turtles with [color = red] [set color yellow] stop] ] ] ] while[mouse-down?] [display] ] ] end to relocate-vertex if not any? vertices [ user-message "There are no vertices" stop ] if mouse-down? [ let candidate min-one-of turtles [distancexy mouse-xcor mouse-ycor] if [distancexy mouse-xcor mouse-ycor] of candidate < 2 [ watch candidate while [mouse-down?] [ display ask subject [ setxy mouse-xcor mouse-ycor ] ] reset-perspective ] ] end to pick-root if not any? vertices [ user-message "You need first to add at least one vertex" stop ] if mouse-down? [ let candidate min-one-of turtles [distancexy mouse-xcor mouse-ycor] if [distancexy mouse-xcor mouse-ycor] of candidate < 2 [ ask candidate [ ask turtles with [size = 4] [set size 3 set color yellow set root? false] set size 4 set color blue + 2 set root? true ] while [mouse-down?] [ display ] ] ] end @#$#@#$#@ GRAPHICS-WINDOW 243 10 1240 608 70 40 7.0 1 20 1 1 1 0 0 0 1 -70 70 -40 40 0 0 1 ticks 30.0 BUTTON 17 35 113 68 Setup setup NIL 1 T OBSERVER NIL S NIL NIL 1 BUTTON 17 87 113 120 Add vertex add-vertex T 1 T OBSERVER NIL V NIL NIL 1 BUTTON 129 87 226 120 Add edge add-edge T 1 T OBSERVER NIL E NIL NIL 1 BUTTON 17 139 112 172 Remove vertex remove-vertex T 1 T OBSERVER NIL NIL NIL NIL 1 BUTTON 128 139 226 172 Remove edge remove-edge T 1 T OBSERVER NIL NIL NIL NIL 1 BUTTON 17 190 114 223 Relocate vertex relocate-vertex T 1 T OBSERVER NIL NIL NIL NIL 1 BUTTON 128 190 226 224 Pick root pick-root T 1 T OBSERVER NIL NIL NIL NIL 1 BUTTON 128 35 224 68 Reset reset NIL 1 T OBSERVER NIL R NIL NIL 1 BUTTON 18 243 114 276 Run BFS go-BFS NIL 1 T OBSERVER NIL B NIL NIL 1 SLIDER 37 298 209 331 delay delay 0 2 0.5 0.05 1 NIL HORIZONTAL BUTTON 129 244 226 277 Run DFS go-DFS NIL 1 T OBSERVER NIL D NIL NIL 1 TEXTBOX 75 376 225 394 NIL 11 0.0 1 OUTPUT 8 351 236 569 12 @#$#@#$#@ ## WHAT IS IT? This is an application that demonstrates 2 basic algortihms for traversing or searching tree or graph: The Depth-first search (DFS) algorithm and the Breadth-first search (BFS) algorithm.You can search any graph you create by simply adding vertices and edges in the GUI. ## HOW IT WORKS Vertices are represented by agents with a circle shape and edges are represented by links between two agents(vertices). You can add as much vertices as you want, create links and then just run of these algorithms. It will show you the entire course of the algorithm. ## HOW TO USE IT Setup - it delets all agents from the previous model, clears up the surface and set up the new model to run Reset - it restores the searched graph to its original state, the roots remains unchanged Add vertex - it allows you to add a vertex by clicking in the green window Add edge - it adds an edge between two selected vertices. Click on one of the vertices, then the other and the edge itself adds Remove vertex - it removes the selected vertex Remove edge - it removes the selected edge. Click on one of the vertices, then the other and the edge between them will be removed Relocate vertex - it allows you to move the vertices and make your graph easy on the eye Pick root - it allows you to pick the root = starting vertex, from which the searching will start Run BFS - it will launch the Breadth-first search algorithm Run DFS - it will launch the Depth-first search algorithm Most of these buttons also have their own hotkeys. Slider delay allows you to change the delay between the individual steps of the algorithm. The output window will show the course of the algorithm. ## EXTENDING THE MODEL It would be great to allow the user to create the graph in the form of matrix and run the searching in this matrix. You could also try to implement a method that would automatically relocate vertices and make the graph easy on the eye. ## NETLOGO FEATURES There is used LIFO and FIFO data structure using primitives as lput, fput, but-first, but-last etc. There are also used links and mouse interaction. ## CREDITS AND REFERENCES Author: Jiri Lukas Email: jirilukas3@seznam.cz Adress: Street: Havlickova 628 Town: Mlada Boleslav Zip code: 29301 State: Czech Republic Continent: Europe Facebook link: https://www.facebook.com/jiri.lukas.7?fref=ts This is my second major project in NetLogo, the first was Checkers Ai vs. Ai (http://ccl.northwestern.edu/netlogo/models/community/Checkers). The third one (traffic simulation) is in the process. If you have any questions or comments please feel free to write me an email or contact me on facebook. @#$#@#$#@ default true 0 Polygon -7500403 true true 150 5 40 250 150 205 260 250 airplane true 0 Polygon -7500403 true true 150 0 135 15 120 60 120 105 15 165 15 195 120 180 135 240 105 270 120 285 150 270 180 285 210 270 165 240 180 180 285 195 285 165 180 105 180 60 165 15 arrow true 0 Polygon -7500403 true true 150 0 0 150 105 150 105 293 195 293 195 150 300 150 box false 0 Polygon -7500403 true true 150 285 285 225 285 75 150 135 Polygon -7500403 true true 150 135 15 75 150 15 285 75 Polygon -7500403 true true 15 75 15 225 150 285 150 135 Line -16777216 false 150 285 150 135 Line -16777216 false 150 135 15 75 Line -16777216 false 150 135 285 75 bug true 0 Circle -7500403 true true 96 182 108 Circle -7500403 true true 110 127 80 Circle -7500403 true true 110 75 80 Line -7500403 true 150 100 80 30 Line -7500403 true 150 100 220 30 butterfly true 0 Polygon -7500403 true true 150 165 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30 30 240 cow false 0 Polygon -7500403 true true 200 193 197 249 179 249 177 196 166 187 140 189 93 191 78 179 72 211 49 209 48 181 37 149 25 120 25 89 45 72 103 84 179 75 198 76 252 64 272 81 293 103 285 121 255 121 242 118 224 167 Polygon -7500403 true true 73 210 86 251 62 249 48 208 Polygon -7500403 true true 25 114 16 195 9 204 23 213 25 200 39 123 cylinder false 0 Circle -7500403 true true 0 0 300 dot false 0 Circle -7500403 true true 90 90 120 face happy false 0 Circle -7500403 true true 8 8 285 Circle -16777216 true false 60 75 60 Circle -16777216 true false 180 75 60 Polygon -16777216 true false 150 255 90 239 62 213 47 191 67 179 90 203 109 218 150 225 192 218 210 203 227 181 251 194 236 217 212 240 face neutral false 0 Circle -7500403 true true 8 7 285 Circle -16777216 true false 60 75 60 Circle -16777216 true false 180 75 60 Rectangle -16777216 true false 60 195 240 225 face sad false 0 Circle -7500403 true true 8 8 285 Circle -16777216 true false 60 75 60 Circle -16777216 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75 260 89 269 108 261 124 240 105 225 105 210 105 Polygon -10899396 true false 105 90 75 75 55 75 40 89 31 108 39 124 60 105 75 105 90 105 Polygon -10899396 true false 132 85 134 64 107 51 108 17 150 2 192 18 192 52 169 65 172 87 Polygon -10899396 true false 85 204 60 233 54 254 72 266 85 252 107 210 Polygon -7500403 true true 119 75 179 75 209 101 224 135 220 225 175 261 128 261 81 224 74 135 88 99 vertex false 0 Circle -13345367 true false 0 0 300 Circle -7500403 true true 15 15 270 Circle -13345367 false false 15 15 270 wheel false 0 Circle -7500403 true true 3 3 294 Circle -16777216 true false 30 30 240 Line -7500403 true 150 285 150 15 Line -7500403 true 15 150 285 150 Circle -7500403 true true 120 120 60 Line -7500403 true 216 40 79 269 Line -7500403 true 40 84 269 221 Line -7500403 true 40 216 269 79 Line -7500403 true 84 40 221 269 wolf false 0 Polygon -16777216 true false 253 133 245 131 245 133 Polygon -7500403 true true 2 194 13 197 30 191 38 193 38 205 20 226 20 257 27 265 38 266 40 260 31 253 31 230 60 206 68 198 75 209 66 228 65 243 82 261 84 268 100 267 103 261 77 239 79 231 100 207 98 196 119 201 143 202 160 195 166 210 172 213 173 238 167 251 160 248 154 265 169 264 178 247 186 240 198 260 200 271 217 271 219 262 207 258 195 230 192 198 210 184 227 164 242 144 259 145 284 151 277 141 293 140 299 134 297 127 273 119 270 105 Polygon -7500403 true true -1 195 14 180 36 166 40 153 53 140 82 131 134 133 159 126 188 115 227 108 236 102 238 98 268 86 269 92 281 87 269 103 269 113 x false 0 Polygon -7500403 true true 270 75 225 30 30 225 75 270 Polygon -7500403 true true 30 75 75 30 270 225 225 270 @#$#@#$#@ NetLogo 5.0.3 @#$#@#$#@ @#$#@#$#@ @#$#@#$#@ setup go count turtles @#$#@#$#@ @#$#@#$#@ default 0.0 -0.2 0 1.0 0.0 0.0 1 1.0 0.0 0.2 0 1.0 0.0 link direction true 0 Line -7500403 true 150 150 90 180 Line -7500403 true 150 150 210 180 @#$#@#$#@ 0 @#$#@#$#@