factorization-with-karel

Variables

Coordinate representation: (a, b)

Inputs and Outputs

• (0, 0) -> The number to factorize
• (1~, 0) -> Prime factors of the number
• (0, 1~) -> Copies of (0, 0)

Flags and data for compute

• (1, 1) -> If (0, 0) can be divided with current factor
• (1, 2) -> If (0, 0) cannot be divided with current factor
• (2, 1) -> Return value of pickBeeperChecked, when the function is called, it will be true and when beepers are picked, it will be false

Constants

• (End, End) -> Must be zero, will be used for [#using-while-clause-as-a-if-clause]
• (End, 0) -> Must be one, will be used for [#using-while-clause-as-a-if-clause]

Using while clause as a if clause

At some reasons, I can't use if clause. But while is allowed, so I thought about "the condition must be false when the while clause end.".

To achive this, when the while clause end, karel must be on (End, End).

Algorithm

• Put beepers count to factorize (This will be input)
• Divide with Pn
  • If number is not divided, progress to Divide with Pn+1
  • Else
    • If (0, 0) == 1, End program with cleanup
    • Else, go to Divide with Pn

Divide with Pn

• Repeat
  • Go to dist (first blank at (1~, 0)), we will call this cell "(dist, 0)"
  • Place a beeper
  • Go to (0, 0)
  • Pick Pn beepers with checked pickBeeper
    • If check failed, do not pick beeper and go to (End, End)
    • Else, put beeper at (1, 1) and go to (End, End)
• If (1, 1) is true, clear (0, 0~) and move (dist, 0) to (0, 0)
• Else, clear (dist, 0) and make (0, 0) to before function call

Code convention

All functions must keep rotation of karel. The functions called by main function must keep position of karel.

Limitation

• Prime count