Dijkstra's Shortest Path Algorithm

patches-own [dist value]
globals [notVisited]

to setup
  ca
  ask patches[
   set dist 99999
   set value random 10 + 1
   set plabel dist
  ]
  ask patch min-pxcor max-pycor [
    set dist 0
  ]
  set notVisited patches
end 

to go
  while [count notVisited > 0]
  [
    let current min-one-of notVisited [dist]
    ask current [set pcolor white set plabel dist]
    ask current [
      ask neighbors4 [
        let newDist ([dist] of myself + value)
        if newDist < dist
        [set dist newDist]
      ]

    ]
    set notVisited notVisited with [self != current]
    ask patches with [dist < 99999][set pcolor gray]
  ]

  crt 1[
    set color red
    setxy max-pxcor min-pycor
    pd
    while[patch-here != patch min-pxcor max-pycor][
    face min-one-of neighbors4 [dist]
    fd 1
      set pcolor color
    ]
  ]
end