Create multiple_visitation_bfs.js

[Gauranshi]

 var util  = require('../core/Util');
    var DiagonalMovement = require('../core/DiagonalMovement');
    function multiple_visitation_bfs(opt) {
      opt = opt || {
      },
      this.allowDiagonal = opt.allowDiagonal
      
    }
    
  var PL=10000000;
  var p=[];


 multiple_visitation_bfs.prototype.findPath=function(startx,starty,endx,endy, grid) {

  diagonalMovement = this.allowDiagonal,
  start = grid.getNodeAt(startx,starty),
  end = grid.getNodeAt(endx,endy);
  var stops=[];
 
  for(var i=0;i<40;i++){

  for(var j=0;j<60;j++){
  if(grid.isNstopAt(j,i)==0){stops.push(grid.getNodeAt(j,i));}
  }
  }
  var vis=new Map([[start,1]]); //visited map
 
  var par =new Map([[start,-1]]);//parent map
  var final=[];
  
  var node=start;
  multi2=function(start,vis,stops,grid,diag){ //greedy function choosing the nearest node from start node
   var prev=[];
  var pr=100000000;
  var node=start;
  for(var i=0;i<stops.length;i++){
    if(!(vis.has(stops[i])) || !(vis.get(stops[i]))){
    var x=bfs(start,stops[i],grid,diag);
    if(x.length<pr){
      pr=x.length;
      prev=x;
      node=stops[i];
    }}
  }

  vis.set(node,1);
  
  return prev;}
 
  final.push(start);
  var x1=multi2(node,vis,stops,grid,this.allowDiagonal);
  while(x1.length){

   for(var i=0;i<x1.length-1;i++){final.push(x1[i]);}
   final.push(x1[i]);
   node=final[final.length-1];
  
   x1=multi2(node,vis,stops,grid,this.allowDiagonal);
  }
  
  var ff=bfs(node,end,grid,this.allowDiagonal);

   for(var i=0;i<ff.length;i++){final.push(ff[i]);}
 
 var e = [
  [final[0].x,
  final[0].y]
]; 

for(var i=1;i<final.length;i++){
    e.push([final[i].x,final[i].y]);
   
    
}

return e;
 
    
  },
  
  bfs=  function(start,end,grid,diag){//function for finding the min path b/w start and end nodes
  var x=[];
  var vi=new Map([[start,1]]);//visited map
  var parent=new Map([]);//parent map
  var queue=[];
  queue.push(start);
  while(queue.length){
      var t1=queue.shift();
      if(t1==end){

          //storing the shoretst path in an array
          while(t1!=start){
              x.push(t1);
              t1=parent.get(t1);
              
          }
          
          x.reverse();
          return x;
      }
      var ne=[];
     
      ne = grid.getNeighbors(t1,diag);
      for (var i = 0;i<ne.length; ++i) {
          neighbor = ne[i];
      ne = grid.getNeighbors(t1,diag);
      for (var i = 0;i<ne.length; ++i) {
          neighbor = ne[i];

          // skip this neighbor if it has been inspected before
          if (vi.has(neighbor)) {
              continue;
          }

          queue.push(neighbor);
          vi.set(neighbor,1);
          parent.set(neighbor,t1);
        
      }
  
  }

};
module.exports = multiple_visitation_bfs;