randgraph <- function(n){
  arr <- sample(0:1,n*n,replace=T)
  mat <- matrix(arr, nrow = n, ncol = n)
  for (i in 1:n)
  {
    mat[i,i]<-0
    for (j in 1:i)
    {
      mat[i,j]<-mat[j,i]
    }
  }
  return(mat)
}



randompoints <- function(n){
  return(sample(-10:10,n,replace=F))
}

distance<-function(xa,ya,xb,yb){
  lev<-sqrt((xa-xb)^2+(ya-yb)^2)
  return(lev)
}


edgedistance<-function(n,graph,X,Y){
  count<-1
  ed<-c()
  for(i in 1:n){
    for(j in 1:n)
    if((graph[i][j] == 1)&&(i<j)){
      z<-distance(X[i],Y[i],X[j],Y[j])
        z<-format(z,digits=2)
      ed<-c(ed,z)
      count<-count+1
    }
  }
  format(1.23456,digits=3)
    return(ed)
}


best_neighbour<-function(graph,colors,X,Y,node_number,finish_node_number){
  n = length(colors)
  min_distance_to_finish_node <- Inf
  output_node_number <- NaN
  for(i in 1:n){
    if(graph[node_number][i] == 1){
      node_distance <- distance(X[finish_node_number],Y[finish_node_number],X[i],Y[i])
      if((node_distance < min_distance_to_finish_node ) && (colors[i]!="red")){
        min_distance_to_finish_node <- node_distance
        output_node_number <- i
      }
    }
  }

  return(output_node_number)
}


greedywalk<-function(n,start_node_number,finish_node_number){
  print("lol2")
  adjacency_matrix <- randgraph(n)
  print(adjacency_matrix)
  graph <- graph.adjacency(adjacency_matrix, mode = "undirected")
  print(graph)
  colors<-1:n
  for (i in 1:n){
    colors[i]<-"white"
  }
  X<-randompoints(n)
  Y<-randompoints(n)
  ed<-edgedistance(n,graph,X,Y)
  our<-matrix(c(X,Y),nrow=n,ncol=2)        #test
  print(X)                                   #Debug
  print(Y)
  colors[start_node_number]<-"red"
  igraph_options(vertex.color=colors)
  plot.igraph(graph,axes=T,layout=norm_coords(our, xmin = -10, xmax = 10, ymin = -10, ymax = 10
  ))
  saveHTML({
  igraph_options(vertex.color=colors)
  plot.igraph(graph,axes=T,layout=norm_coords(our, xmin = -10, xmax = 10, ymin = -10, ymax = 10
  ))
  best_neighbour_node <- start_node_number
  distance_to_finish_node <- 1
  while(distance_to_finish_node!=0){
    best_neighbour_node<-best_neighbour(graph,colors,X,Y,best_neighbour_node,finish_node_number)
    if (is.nan(best_neighbour_node) == TRUE){
      print("Your graph is fucked up.")
    }
    colors[best_neighbour_node]<-"red"
    igraph_options(vertex.color=colors)
    plot.igraph(graph,axes=T,layout=norm_coords(our, xmin = -10, xmax = 10, ymin = -10, ymax = 10
    ))
    distance_to_finish_node<-distance(X[finish_node_number],Y[finish_node_number],X[best_neighbour_node],Y[best_neighbour_node])
  }},img.name="Greedywalk",ani.type="png",htmlfile="GreedyWalk.html",imgdir="images222",autoplay=F,
  interval=0.5,title = "GreedyWalk")
  igraph_options(vertex.color=colors)
  plot.igraph(graph,axes=T,layout=norm_coords(our, xmin = -10, xmax = 10, ymin = -10, ymax = 10
  ),edge.label=ed,edge.width = 1.4,edge.color = 'black')
  print('fine')
  grid(NULL, NULL)
  return(distance_to_finish_node)
}