code: def planting_trees(trees, length, width):
      """
      Returns the minimum distance that trees have to be moved before they
      are all in a valid state.
  
          Parameters:
              tree (list<int>): A sorted list of integers with all trees'
                                position along the road.
              length (int): An integer with the length of the road.
              width (int): An integer with the width of the road.
  
          Returns:
              A float number with the total distance trees have been moved.
      """
      trees = [0] + trees
  
      n_pairs = int(len(trees) / 2)
  
      space_between_pairs = length / (n_pairs - 1)
  
      target_locations = [
          location * space_between_pairs for location in range(n_pairs)
      ]
  
      cmatrix = [
          [0 for _ in range(n_pairs + 1)] for _ in range(n_pairs + 1)
      ]
      for r_i in range(1, n_pairs + 1):
          cmatrix[r_i][0] = cmatrix[r_i - 1][0] + sqrt(
              width + abs(trees[r_i] - target_locations[r_i - 1]) ** 2
          )
      for l_i in range(1, n_pairs + 1):
          cmatrix[0][l_i] = cmatrix[0][l_i - 1] + abs(
              trees[l_i] - target_locations[l_i - 1]
          )
  
      for r_i in range(1, n_pairs + 1):
          for l_i in range(1, n_pairs + 1):
              cmatrix[r_i][l_i] = min(
                  cmatrix[r_i - 1][l_i]
                  + sqrt(
                      width
                      + (trees[l_i + r_i] - target_locations[r_i - 1])
                      ** 2
                  ),
                  cmatrix[r_i][l_i - 1]
                  + abs(trees[l_i + r_i] - target_locations[l_i - 1]),
              )
  
      return cmatrix[n_pairs][n_pairs]
  
label_desc: Use image node_id 1 for calling a global function with example usage: planting_trees(trees, length, width) and returns: cmatrix