add r assignments from course

assignment_1.r

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+library(DeliveryMan)
+
+create_node <- function(posX, posY, cost = .Machine$integer.max) {
+  return(list(x = posX, y = posY, cost = cost))
+}
+
+distance <- function (x1, y1, x2, y2){
+  return(abs(x1 - x2) + abs(y1 - y2))
+}
+
+myFunction <- function(roads, car, packages) {
+  # roads-> list of two matrixes for traffic conditions hroads and vroads (coordintes bottom left to top right )
+  # coordinates stat <1,1> and go to <dim,dim>
+  # list of information about your car -> load -> mem -> nextMove 
+  # matrix about packages
+  car$nextMove = 5
+  
+  destX = 1
+  destY = 1
+  if(car$load == 0) {
+    # closest package
+    distances = distance(car$x, car$y, packages[,1], packages[,2])
+    # set packages we already collected to infinite distance
+    distances[packages[, 5] != 0] = .Machine$integer.max 
+    minDistanceIndex = which.min(distances)
+    destX = packages[minDistanceIndex, 1]
+    destY = packages[minDistanceIndex, 2]
+    
+  } else {
+    destX = packages[car$load, 3]
+    destY = packages[car$load, 4]   
+  }
+  path = find_path(car$x, car$y, destX, destY, roads)
+  nextPoint = path[[1]]
+  car$nextMove = next_move(car$x, car$y, nextPoint$x, nextPoint$y)
+  return(car)
+}
+
+get_neighbour <- function(posX, posY, cameFromX, cameFromY, goalX, goalY, costToNode) {
+  totalCost = costToNode + distance(posX, posY, goalX, goalY)
+  toVisit = TRUE
+  return(create_node_info_element(posX, posY, cameFromX, cameFromY, costToNode, totalCost, toVisit =TRUE))
+}
+
+get_neighbours <- function (posX, posY, goalX, goalY, costToParentNode, roads) {
+  maxY = length(roads$hroads[1,])
+  maxX = length(roads$vroads[,1])
+  
+  n1 = NULL
+  n2 = NULL
+  n3 = NULL
+  n4 = NULL
+  
+  if (posX > 1) {
+    cost = roads$hroads[posX-1, posY] + costToParentNode
+    n1 = create_node(posX-1,posY, cost)
+  }
+  if (posX < maxX) {
+    cost = roads$hroads[posX, posY] + costToParentNode
+    n2 = create_node(posX + 1, posY, cost)
+  }
+  if (posY > 1) {
+    cost = roads$vroads[posX, posY - 1] + costToParentNode
+    n3 = create_node(posX,posY - 1, cost)
+  }
+  if (posY < maxY) {   
+    cost = roads$vroads[posX, posY] + costToParentNode
+    n4 = create_node(posX,posY + 1, cost)
+  }
+  return(list(n1, n2, n3, n4))
+}
+
+find_path <- function (startX, startY, goalX, goalY, roads) {
+  pq_cost = c()
+  pq_list = list()
+  
+  maxX = length(roads$vroads[,1])
+  maxY = length(roads$hroads[1,])
+  cameFromX <<- matrix(0, nrow = maxX, ncol = maxY)
+  cameFromY <<- matrix(0, nrow = maxX, ncol = maxY)
+  costToNode <<- matrix(.Machine$double.xmax, nrow = maxX, ncol = maxY)
+  visited <<- matrix(FALSE, nrow = maxX, ncol = maxY)
+  
+  maxY = length(roads$hroads[1,])
+  maxX = length(roads$vroads[,1])
+
+  cost = 0
+  node = create_node(startX, startY, 0)
+  # priority queue insert
+  insert.order <- findInterval(cost, pq_cost)
+  pq_cost <- append(pq_cost, cost, insert.order)
+  pq_list <- append(pq_list, list(node), insert.order)
+
+  
+  costToNode[startX, startY] = 0
+  cameFromX[startX, startY] = startX
+  cameFromY[startX, startY] = startY
+  
+  current = NULL
+  while (length(pq_cost) != 0) {
+    # pop queue
+    current <- pq_list[[1]]
+    pq_cost <- pq_cost[-1]
+    pq_list <- pq_list[-1]
+    
+    if (current$x == goalX & current$y == goalY) {
+      path_list = NULL
+      # walk backwards until starting element is reached
+      while (current$x != startX | current$y != startY) {
+        # get next element
+        path_list = append(list(current), path_list)
+        current = create_node(cameFromX[current$x, current$y], cameFromY[current$x, current$y], costToNode[current$x, current$y])
+      }
+      return(path_list)
+    }
+    
+    neighbours = get_neighbours(current$x, current$y, goalX, goalY, costToNode[current$x, current$y], roads)
+    
+    for(n in neighbours) {
+      if(is.null(n) == FALSE) {
+        if(n$cost < costToNode[n$x, n$y]) {
+          cameFromX[n$x,n$y] = current$x
+          cameFromY[n$x,n$y] = current$y
+          
+          costToNode[n$x, n$y] = n$cost
+          
+          totalCost = n$cost + distance(n$x, n$y, goalX, goalY)
+          
+          # priority queue insert
+          insert.order <- findInterval(totalCost, pq_cost)
+          pq_cost <- append(pq_cost, totalCost, insert.order)
+          pq_list <- append(pq_list, list(n), insert.order)
+        }
+      }
+    }
+    
+  }
+  #Failed to find path
+  return(NULL)
+}
+
+next_move <- function(carX, carY, dirX, dirY) {
+  if(!is.numeric(dirX) || !is.numeric(dirY)) {
+    return(0)
+  }
+  xDir = carX - dirX
+  yDir = carY - dirY
+  
+  if (xDir + yDir < 0) {
+    if (xDir == 0) {
+      # up
+      return(8)
+    } else {
+      # right
+      return(6)
+    }
+  } else if (xDir + yDir > 0){
+    if (xDir == 0) {
+      # down
+      return(2)
+    } else {
+      # left
+      return(4)
+    }
+  }
+  return(0)
+}
+
+startTime = Sys.time()
+print(testDM(myFunction, timeLimit = 250))
+endTime = Sys.time()
+print(endTime - startTime)