# Week I: Lecture Notes

## Agenda
- Introductions
- Hospital Karel
- Future Directions

## Notes
Put anything here!
- Can spill over 40 minutes

### IDE
- Pycharm
- Other

### Send out Handouts
- For now, lets use [the web](https://compedu.stanford.edu/codeinplace/v1/#/karel/section1/hospital)

## Pseudocode

### Main Tasks
- [x] Build Hospitals
- [x] Build a hospital -> function
- [x] Find beepers -> conditions
- Or atleast be aware of them
- [x] Reset -> function (with conditions)
- Movement Helpers
- [x] Turn right -> function
- [x] World traversal

#### Turn Right

- First attempt

def turn_right():
   turn_left()
   turn_left()
   turn_left()

- Production go

def turn_right():
   for i in range(3):
      turn_left()

##### Bonus (with while)
- Make it shorter with loops

#### World Traversal

##### For
- Hit an error at the end
- Manually counting squares

for i in range(200):
    move()

- Such a large number means we should probably use a while
- We **do not** recognize the end state

def main():
   for i in range(200):
      if (front_is_clear()):
         move()
      else:
         turn_right()
# Does funny things

##### While

- We encode the **end state recognition**

def main():
   while(front_is_clear()):
      move()

##### Find Beepers
- Is true if karel is on a beeper

def main():
   while(front_is_clear()):
      move()
      if (beepers_present()):
         turn_left()

##### Building Hospitals

- Start to build
- Can we use for?

We now realize we need

   turn_left()
   for i in range(2):
      move()
      put_beeper()

###### Two Ways
- Is a hospital 2 columns of 3 beepers?
- Is a hospital 2 beepers up and 3 down?

##### Build Column 1

def build_column1():
   turn_left()
   for i in range(2):
      move()
      put_beeper()

#### Build Column 2

def build_column2():
   put_beeper()
   for i in range(2):
      move()
      put_beeper()

When we need a function to exist for the program to run but haven't defined it yet.

def i_exist():
    pass

### Alternative

2 columns, 3 beepers high

If you're at a beeper, pick it up.

#### Goto Bottom

def goto_bottom():
   for i in range(4):
      turn_left()
      if(facing_south()):
         while(front_is_clear()):
         move()

The whole function:

def build_hospital():
   pick_beeper()
   turn_left()
   build_column2()
   reset()
   move()
   turn_left()
   build_column2()
   reset()

# Full code

from karel.stanfordkarel import *

# File: hospital.py
# -----------------------------
# Here is a place to program your section problem
def main():
   while(front_is_clear()):
      move()
      if (beepers_present()):
      build_hospital_2col()

def build_hospital_colreset():
   pick_beeper()
   turn_left()
   build_column2()
   reset()
   move()
   turn_left()
   build_column2()
   reset()

def build_hospital_2col():
   build_column1()
   turn_right()
   move()
   turn_right()
   build_column2()
   turn_left()
   
def build_column1():
   turn_left()
   for i in range(2):
      move()
      put_beeper()
   
def build_column2():
   put_beeper()
   for i in range(2):
      move()
      put_beeper()
      
def reset():
   goto_bottom()
   turn_right()

def goto_bottom():
   for i in range(4):
      turn_left()
      if(facing_south()):
         while(front_is_clear()):
         move()

def turn_right():
   for i in range(3):
      turn_left()