3 Missionaries and 3 cannibals - crossing the river

3 missionaries (or sheep or carrots) and 3 cannibals (or wolves or rabbits) stand on a riverbank. On
the same riverbank a boat, that can maximally take 2 persons (minimally 1), lies. The 6 people are
facing a problem: how to optimally transport (minimal number of moves) ourselves from
the current riverbank (the left one) to the opposite bank of the river (the right one) in a way
that guarantees that at any time the number of cannibals never outnumber the number of
missionaries (they will then be eaten)?

The missionaries and cannibal problem is a popular problem used in Artificial intelligence to understand and experiment with search methods. Here is a list of the possible optimal solutions for the various cases

1 cannibal and 1 missionary

Step1:(left 1 1 0 0)
Step2:(right 0 0 1 1)

2 cannibals and 2 missionaries

Solution1:
((left 2 2 0 0) (right 2 0 0 2) (left 2 1 0 1) (right 0 1 2 1) (left 1 1 1 1) (right 0 0 2 2))

Solution2:
((left 2 2 0 0) (right 1 1 1 1) (left 2 1 0 1) (right 0 1 2 1) (left 0 2 2 0) (right 0 0 2 2))

3 cannibals and 3 missionaries

Solution1:
((left 3 3 0 0)
(right 3 1 0 2)
(left 3 2 0 1)
(right 3 0 0 3)
(left 3 1 0 2)
(right 1 1 2 2)
(left 2 2 1 1)
(right 0 2 3 1)
(left 0 3 3 0)
(right 0 1 3 2)
(left 1 1 2 2)
(right 0 0 3 3))

Solution2:

((left 3 3 0 0)
(right 2 2 1 1)
(left 3 2 0 1)
(right 3 0 0 3)
(left 3 1 0 2)
(right 1 1 2 2)
(left 2 2 1 1)
(right 0 2 3 1)
(left 0 3 3 0)
(right 0 1 3 2)
(left 0 2 3 1)
(right 0 0 3 3))

2 cannibals and 3 missionaries

Solution1:

((left 3 2 0 0)
(right 2 1 1 1)
(left 2 2 1 0)
(right 1 1 2 1)
(left 2 1 1 1)
(right 1 0 2 2)
(left 1 1 2 1)
(right 0 0 3 2))

Solution2:

((left 3 2 0 0)
(right 3 0 0 2)
(left 3 1 0 1)
(right 1 1 2 1)
(left 2 1 1 1)
(right 0 1 3 1)
(left 1 1 2 1)
(right 0 0 3 2))

1 cannibal and 2 missionaries

Solution1:

((left 2 1 0 0) (right 0 1 2 0) (left 1 1 1 0) (right 0 0 2 1))

Solution2:

((left 2 1 0 0) (right 0 1 2 0) (left 1 1 1 0) (right 1 0 1 1) (left 2 0 0 1) (right 0 0 2 1))

0 cannibal and 1 missionaries

((left 1 0 0 0) (right 0 0 1 0))

Solutions are not possible for numbers greater than 3 or cases in which cannibals outnumber missionaries.

Crayon Physics - error - limit on number of drawings

After writing a kind of tutorial on wining the seven different crayon physics puzzles or levels (crayon puzzles) in the demo mode, the game showed few limits, not by itself by the physics engine on which it runs. The error says "You Broke my Game! There's too many objects on the screen . The physics engine can't keep up with it. Unfortunately you will have to restart the level :("

The worst thing about this error is it pops up just when you are able to solve :) the puzzle.

The different levels of the demo are:

1. Tutorial
   
2. The 2 towers
   
3. Tee Ters
   
4. Lots of Space
   
5. Log
   
6. Sky Captain
   
7. Nasty

The background music of the game is pretty melodious and not interfering. The final word is Crayon physics proves beyond doubt tat its an awesomely cool game :)

Crayon Physics - Nasty

The Nasty level in crayon physics has two stars to collect. Although its possible to collect both stars in a single go, this method shows collecting each of the stars in separate goes.

To collect the first star, first block the ball at the top. and create structures as in image below.

Delete the blocking box to collect the first start. The ball falls down and comes for second go. Block the ball and build the next set of structures as in below image.

Draw both structures together along with guarding wall at the left bottom corner to collect both stars in a single go.

Crayon Physics - Sky Captain

Sky captain can be solved similar to TEE TERS by balancing the see saws and then setting the ball rolling. But make sure the right side is having some weight to counteract the weight of the square tat gets the ball rolling.

The seesaws can be balanced using a single beam or two separate beams. But make sure to use long beams to get them balanced.

Crayon Physics - Log

The Log can be solved very easily by removing the log and then setting the ball roll. However, can anybody solve it without making the log fall? The acclaimed tunneling effect from quantum physics is required for this :) Any quantum physicists out there? can u do it?

Anyway for the rest of us the easy solution is given below. First get the log out of the way by dropping beams on top of it. Then just get the ball rolling to collect the star.


If any of you quantum physicists can do the tunneling effect without making the log fall, do let me know how u did it.

Crayon Physics - Lots Of Space

Lots of space seemed a bit difficult to solve to begin with as it required the drawing of boxes of exact sizes so tat the weight got balanced. If you draw a box tats too small or too big, they will both go tumbling down. The challenge is to fill the space and make the ball roll.
Draw the leftmost vertical box first and make it stand properly. Next draw the slant pole so tat it gets balanced by the vertical box. Once the the two boxes get balanced, draw a third box to get the ball rolling.

A much easier way is to draw multiple boxes to make the levels nearly equal, and drawing a pole connecting the two. Then once the ball comes near the piled up boxes, delete them quickly so tat the ball falls on top of the star.

The way2 to solve lots of space teaches cantilever concept.
So lot of physics learning going on with the crayon.

Crayon Physics - tee ters

The third puzzle called the Teeters or TEE TERS can be solved by drawing a single bar that balances and equalises the two see saws and drawing another box to get the ball rolling.


This seems to be the simplest solution. So should we try to solve the puzzle by drawing the least number of stuffs? is tat the aim of the game? well tat would make the game boring and does not make the full use of the artistic power of Crayon Physics.

Crayon physics demo - the 2 towers

As if solving the first puzzle was not easy enough, the second puzzle can be solved like below. Just need to draw two boxes. One Box connecting the two towers and another to set the ball rolling.



This seems to be like a tutorial to solving the demo version of crayon physics, but dont limit your creativity to these solutions. Do explore more fun ways to solve these puzzles.

Actually dont just think of these as puzzles, they are a kind of art with purpose. The purpose of the art is to collect the star:) So wat are u waiting for pickup the crayons and start sketching.

Crayon Physics - awesomly talented game

Crayon physics is a really great game that tests your artistic sense and physics. No you dont need to be a particle physicist.

The demo version of the game comes with 7 puzzles and is very simple to learn and fun to play. The aim of the game is to collect stars by making a ball to move towards a star. The first puzzle can be solved easily based on the instructions given in the game background.



This is just one way to solve the game, but the same thing can be solved in innumerable different methods. The beauty of the game is tat its not a science, but an art. We learn handling the mouse, physics and art all at the same time :)

Hit the space bar to reset the game and the esc key to goto the menu. Do let me know if you solve the puzzles in the most artistic ways possible.