205 lines
4.9 KiB
Python
205 lines
4.9 KiB
Python
#!/usr/bin/env python3
|
|
"""
|
|
|
|
sorting_animation.py
|
|
|
|
A minimal sorting algorithm animation:
|
|
Sorts a shelf of 10 blocks using insertion
|
|
sort, selection sort and quicksort.
|
|
|
|
Shelfs are implemented using builtin lists.
|
|
|
|
Blocks are turtles with shape "square", but
|
|
stretched to rectangles by shapesize()
|
|
---------------------------------------
|
|
To exit press space button
|
|
---------------------------------------
|
|
"""
|
|
from turtle import *
|
|
import random
|
|
|
|
|
|
class Block(Turtle):
|
|
|
|
def __init__(self, size):
|
|
self.size = size
|
|
Turtle.__init__(self, shape="square", visible=False)
|
|
self.pu()
|
|
self.shapesize(size * 1.5, 1.5, 2) # square-->rectangle
|
|
self.fillcolor("black")
|
|
self.st()
|
|
|
|
def glow(self):
|
|
self.fillcolor("red")
|
|
|
|
def unglow(self):
|
|
self.fillcolor("black")
|
|
|
|
def __repr__(self):
|
|
return "Block size: {0}".format(self.size)
|
|
|
|
|
|
class Shelf(list):
|
|
|
|
def __init__(self, y):
|
|
"create a shelf. y is y-position of first block"
|
|
self.y = y
|
|
self.x = -150
|
|
|
|
def push(self, d):
|
|
width, _, _ = d.shapesize()
|
|
# align blocks by the bottom edge
|
|
y_offset = width / 2 * 20
|
|
d.sety(self.y + y_offset)
|
|
d.setx(self.x + 34 * len(self))
|
|
self.append(d)
|
|
|
|
def _close_gap_from_i(self, i):
|
|
for b in self[i:]:
|
|
xpos, _ = b.pos()
|
|
b.setx(xpos - 34)
|
|
|
|
def _open_gap_from_i(self, i):
|
|
for b in self[i:]:
|
|
xpos, _ = b.pos()
|
|
b.setx(xpos + 34)
|
|
|
|
def pop(self, key):
|
|
b = list.pop(self, key)
|
|
b.glow()
|
|
b.sety(200)
|
|
self._close_gap_from_i(key)
|
|
return b
|
|
|
|
def insert(self, key, b):
|
|
self._open_gap_from_i(key)
|
|
list.insert(self, key, b)
|
|
b.setx(self.x + 34 * key)
|
|
width, _, _ = b.shapesize()
|
|
# align blocks by the bottom edge
|
|
y_offset = width / 2 * 20
|
|
b.sety(self.y + y_offset)
|
|
b.unglow()
|
|
|
|
def isort(shelf):
|
|
length = len(shelf)
|
|
for i in range(1, length):
|
|
hole = i
|
|
while hole > 0 and shelf[i].size < shelf[hole - 1].size:
|
|
hole = hole - 1
|
|
shelf.insert(hole, shelf.pop(i))
|
|
return
|
|
|
|
def ssort(shelf):
|
|
length = len(shelf)
|
|
for j in range(0, length - 1):
|
|
imin = j
|
|
for i in range(j + 1, length):
|
|
if shelf[i].size < shelf[imin].size:
|
|
imin = i
|
|
if imin != j:
|
|
shelf.insert(j, shelf.pop(imin))
|
|
|
|
def partition(shelf, left, right, pivot_index):
|
|
pivot = shelf[pivot_index]
|
|
shelf.insert(right, shelf.pop(pivot_index))
|
|
store_index = left
|
|
for i in range(left, right): # range is non-inclusive of ending value
|
|
if shelf[i].size < pivot.size:
|
|
shelf.insert(store_index, shelf.pop(i))
|
|
store_index = store_index + 1
|
|
shelf.insert(store_index, shelf.pop(right)) # move pivot to correct position
|
|
return store_index
|
|
|
|
def qsort(shelf, left, right):
|
|
if left < right:
|
|
pivot_index = left
|
|
pivot_new_index = partition(shelf, left, right, pivot_index)
|
|
qsort(shelf, left, pivot_new_index - 1)
|
|
qsort(shelf, pivot_new_index + 1, right)
|
|
|
|
def randomize():
|
|
disable_keys()
|
|
clear()
|
|
target = list(range(10))
|
|
random.shuffle(target)
|
|
for i, t in enumerate(target):
|
|
for j in range(i, len(s)):
|
|
if s[j].size == t + 1:
|
|
s.insert(i, s.pop(j))
|
|
show_text(instructions1)
|
|
show_text(instructions2, line=1)
|
|
enable_keys()
|
|
|
|
def show_text(text, line=0):
|
|
line = 20 * line
|
|
goto(0,-250 - line)
|
|
write(text, align="center", font=("Courier", 16, "bold"))
|
|
|
|
def start_ssort():
|
|
disable_keys()
|
|
clear()
|
|
show_text("Selection Sort")
|
|
ssort(s)
|
|
clear()
|
|
show_text(instructions1)
|
|
show_text(instructions2, line=1)
|
|
enable_keys()
|
|
|
|
def start_isort():
|
|
disable_keys()
|
|
clear()
|
|
show_text("Insertion Sort")
|
|
isort(s)
|
|
clear()
|
|
show_text(instructions1)
|
|
show_text(instructions2, line=1)
|
|
enable_keys()
|
|
|
|
def start_qsort():
|
|
disable_keys()
|
|
clear()
|
|
show_text("Quicksort")
|
|
qsort(s, 0, len(s) - 1)
|
|
clear()
|
|
show_text(instructions1)
|
|
show_text(instructions2, line=1)
|
|
enable_keys()
|
|
|
|
def init_shelf():
|
|
global s
|
|
s = Shelf(-200)
|
|
vals = (4, 2, 8, 9, 1, 5, 10, 3, 7, 6)
|
|
for i in vals:
|
|
s.push(Block(i))
|
|
|
|
def disable_keys():
|
|
onkey(None, "s")
|
|
onkey(None, "i")
|
|
onkey(None, "q")
|
|
onkey(None, "r")
|
|
|
|
def enable_keys():
|
|
onkey(start_isort, "i")
|
|
onkey(start_ssort, "s")
|
|
onkey(start_qsort, "q")
|
|
onkey(randomize, "r")
|
|
onkey(bye, "space")
|
|
|
|
def main():
|
|
getscreen().clearscreen()
|
|
ht(); penup()
|
|
init_shelf()
|
|
show_text(instructions1)
|
|
show_text(instructions2, line=1)
|
|
enable_keys()
|
|
listen()
|
|
return "EVENTLOOP"
|
|
|
|
instructions1 = "press i for insertion sort, s for selection sort, q for quicksort"
|
|
instructions2 = "spacebar to quit, r to randomize"
|
|
|
|
if __name__=="__main__":
|
|
msg = main()
|
|
mainloop()
|