It is time to solve some of the challenges introduced early on.
Using while, if, else, etc., you will write programs that will be able to accomplish various tasks. In writing these programs, you should keep the following in mind:
Now, remember rule #1 ... and make sure that, this time, you solve all the challenges mentioned below.
Important
Make sure you save your various solutions as you might want to come back to them later.
Select world Harvest 4 which occurred shortly after the garden was seeded. Some carrot seeds sprouted well, others yielded two or three plants while some did not sprout at all. Help Reeborg weed out the excess seedlings, and plant some new seeds at locations where some were missing. Here is a suggestion for some vocabulary to use:
Reeborg's World
var carrot_here = token_here;
var plant_carrot_seed = put;
var remove_seedling = take;
function ensure_one_carrot_at_spot(){
...
}
Do it!
Write a program as described above.
The weeding went well (I hope!), the growing season is over and it is time to harvest. Select world Harvest 1 or Harvest 2 and have Reeborg collect all the tokens which represent plants to harvest.
Notice how one can view the world Harvest 1 as having horizontal (or vertical) rows having the same length, while world Harvest 2 can be seen as having diagonal rows having the same length.
One possible approach is to define a function harvest_one_row and a second one called harvest_two_rows as well as move_to_first_row. Using these, can write a general solution. Note that these individual functions may have to be different in different worlds.
With suitable function definitions, the programs for either world Harvest 1 or Harvest 2 can be written as:
move_to_first_row();
repeat(harvest_two_rows, 3);
Note however that you may choose a different way to solve the problems than that which is described above.
Do it!
Write a program to do the harvesting as described.
It was a beautifully sunny day. Reeborg was playing outside with his friend. Suddenly, it started to rain and Reeborg remembered that the windows in his house were all open. So Reeborg went back to his house and stopped in front of the door, unsure of how to proceed.
Do it!
Using the build_wall() instruction, help Reeborg close the windows of his house. When Reeborg finishes his task, he will stand in the doorway, watching the rain fall, waiting for it to stop before he can go back and play outside. The world is Storm 1.
Erdna, Reeborg’s friend, lives in a bigger house as shown on Storm 2. Erdna was playing outside with Reeborg when it started raining. Help Erdna close the windows in her house.
Try it!
Your challenge is to write a single program that will work for both Reeborg and Erdna ... however, it might be a bit tricky.
Hint
To determine if there’s a window at a given location, a robot may have to take an extra step and, depending on the result, may have to turn around, go back and close that window.
The wind blew really hard last night. There is litter everywhere outside Reeborg’s house. His parents asked him to go and clean up the path leading to the curb, Storm 3, as well as the driveway: Storm 4.
Do it!
Following the instructions in your program, Reeborg should collect all the litter, and put it in the garbage can, and close the lid, using build_wall().
Reeborg’s parents are so proud of his work, that they ask him to pick up all the garbage that got blown away in their backyard during the windstorm, as illustrated on Storm 5. Have Reeborg pick up all the garbage and put it in the garbage can.
Try it!
Your real challenge is to write a single program that can help Reeborg do the cleanup for all three locations.
Have a look at the worlds Center 1 to Center 3.
Do this!
Write a single program that has Reeborg put a token at the geometric center of the rectangular room he finds himself in.
Hint
You may find it useful to have Reeborg, who carries two tokens, drop one token at each end of a line. Then, by picking one token at one end and moving it one step, going back and forth until both tokens are at the same position, the location of the center can be found. When you know how to do this in one dimension (along a horizontal line), you can use that location as the starting point to find the location along the other location (a vertical line).