#! /usr/bin/env python
"""Sorting algorithms visualizer using Tkinter.
This module is comprised of three ``components'':
- an array visualizer with methods that implement basic sorting
operations (compare, swap) as well as methods for ``annotating'' the
sorting algorithm (e.g. to show the pivot element);
- a number of sorting algorithms (currently quicksort, insertion sort,
selection sort and bubble sort, as well as a randomization function),
all using the array visualizer for its basic operations and with calls
to its annotation methods;
- and a ``driver'' class which can be used as a Grail applet or as a
stand-alone application.
"""
from tkinter import *
from Canvas import Line,Rectangle
import random
XGRID = 10
YGRID = 10
WIDTH = 6
class Array:
def __init__(self, master, data=None):
self.master = master
self.frame = Frame(self.master)
self.frame.pack(fill=X)
self.label = Label(self.frame)
self.label.pack()
self.canvas = Canvas(self.frame)
self.canvas.pack()
self.report = Label(self.frame)
self.report.pack()
self.left = Line(self.canvas, 0, 0, 0, 0)
self.right = Line(self.canvas, 0, 0, 0, 0)
self.pivot = Line(self.canvas, 0, 0, 0, 0)
self.items = []
self.size = self.maxvalue = 0
if data:
self.setdata(data)
def setdata(self, data):
olditems = self.items
self.items = []
for item in olditems:
item.delete()
self.size = len(data)
self.maxvalue = max(data)
self.canvas.config(width=(self.size+1)*XGRID,
height=(self.maxvalue+1)*YGRID)
for i in range(self.size):
self.items.append(ArrayItem(self, i, data[i]))
self.reset("Sort demo, size %d" % self.size)
speed = "normal"
def setspeed(self, speed):
self.speed = speed
def destroy(self):
self.frame.destroy()
in_mainloop = 0
stop_mainloop = 0
def cancel(self):
self.stop_mainloop = 1
if self.in_mainloop:
self.master.quit()
def step(self):
if self.in_mainloop:
self.master.quit()
Cancelled = "Array.Cancelled" # Exception
def wait(self, msecs):
if self.speed == "fastest":
msecs = 0
elif self.speed == "fast":
msecs = msecs//10
elif self.speed == "single-step":
msecs = 1000000000
if not self.stop_mainloop:
self.master.update()
id = self.master.after(msecs, self.master.quit)
self.in_mainloop = 1
self.master.mainloop()
self.master.after_cancel(id)
self.in_mainloop = 0
if self.stop_mainloop:
self.stop_mainloop = 0
self.message("Cancelled")
raise Array.Cancelled
def getsize(self):
return self.size
def show_partition(self, first, last):
for i in range(self.size):
item = self.items[i]
if first <= i < last:
item.item.config(fill='red')
else:
item.item.config(fill='orange')
self.hide_left_right_pivot()
def hide_partition(self):
for i in range(self.size):
item = self.items[i]
item.item.config(fill='red')
self.hide_left_right_pivot()
def show_left(self, left):
if not 0 <= left < self.size:
self.hide_left()
return
x1, y1, x2, y2 = self.items[left].position()
## top, bot = HIRO
self.left.coords([(x1-2, 0), (x1-2, 9999)])
self.master.update()
def show_right(self, right):
if not 0 <= right < self.size:
self.hide_right()
return
x1, y1, x2, y2 = self.items[right].position()
self.right.coords(((x2+2, 0), (x2+2, 9999)))
self.master.update()
def hide_left_right_pivot(self):
self.hide_left()
self.hide_right()
self.hide_pivot()
def hide_left(self):
self.left.coords(((0, 0), (0, 0)))
def hide_right(self):
self.right.coords(((0, 0), (0, 0)))
def show_pivot(self, pivot):
x1, y1, x2, y2 = self.items[pivot].position()
self.pivot.coords(((0, y1-2), (9999, y1-2)))
def hide_pivot(self):
self.pivot.coords(((0, 0), (0, 0)))
def swap(self, i, j):
if i == j: return
self.countswap()
item = self.items[i]
other = self.items[j]
self.items[i], self.items[j] = other, item
item.swapwith(other)
def compare(self, i, j):
self.countcompare()
item = self.items[i]
other = self.items[j]
return item.compareto(other)
def reset(self, msg):
self.ncompares = 0
self.nswaps = 0
self.message(msg)
self.updatereport()
self.hide_partition()
def message(self, msg):
self.label.config(text=msg)
def countswap(self):
self.nswaps = self.nswaps + 1
self.updatereport()
def countcompare(self):
self.ncompares = self.ncompares + 1
self.updatereport()
def updatereport(self):
text = "%d cmps, %d swaps" % (self.ncompares, self.nswaps)
self.report.config(text=text)
class ArrayItem:
def __init__(self, array, index, value):
self.array = array
self.index = index
self.value = value
x1, y1, x2, y2 = self.position()
self.item = Rectangle(array.canvas, x1, y1, x2, y2,
fill='red', outline='black', width=1)
self.item.bind('<Button-1>', self.mouse_down)
self.item.bind('<Button1-Motion>', self.mouse_move)
self.item.bind('<ButtonRelease-1>', self.mouse_up)
def delete(self):
item = self.item
self.array = None
self.item = None
item.delete()
def mouse_down(self, event):
self.lastx = event.x
self.lasty = event.y
self.origx = event.x
self.origy = event.y
self.item.tkraise()
def mouse_move(self, event):
self.item.move(event.x - self.lastx, event.y - self.lasty)
self.lastx = event.x
self.lasty = event.y
def mouse_up(self, event):
i = self.nearestindex(event.x)
if i >= self.array.getsize():
i = self.array.getsize() - 1
if i < 0:
i = 0
other = self.array.items[i]
here = self.index
self.array.items[here], self.array.items[i] = other, self
self.index = i
x1, y1, x2, y2 = self.position()
self.item.coords(((x1, y1), (x2, y2)))
other.setindex(here)
def setindex(self, index):
nsteps = steps(self.index, index)
if not nsteps: return
if self.array.speed == "fastest":
nsteps = 0
oldpts = self.position()
self.index = index
newpts = self.position()
trajectory = interpolate(oldpts, newpts, nsteps)
self.item.tkraise()
for pts in trajectory:
self.item.coords((pts[:2], pts[2:]))
self.array.wait(50)
def swapwith(self, other):
nsteps = steps(self.index, other.index)
if not nsteps: return
if self.array.speed == "fastest":
nsteps = 0
myoldpts = self.position()
otheroldpts = other.position()
self.index, other.index = other.index, self.index
mynewpts = self.position()
othernewpts = other.position()
myfill = self.item['fill']
otherfill = other.item['fill']
self.item.config(fill='green')
other.item.config(fill='yellow')
self.array.master.update()
if self.array.speed == "single-step":
self.item.coords((mynewpts[:2], mynewpts[2:]))
other.item.coords((othernewpts[:2], othernewpts[2:]))
self.array.master.update()
self.item.config(fill=myfill)
other.item.config(fill=otherfill)
self.array.wait(0)
return
mytrajectory = interpolate(myoldpts, mynewpts, nsteps)
othertrajectory = interpolate(otheroldpts, othernewpts, nsteps)
if self.value > other.value:
self.item.tkraise()
other.item.tkraise()
else:
other.item.tkraise()
self.item.tkraise()
try:
for i in range(len(mytrajectory)):
mypts = mytrajectory[i]
otherpts = othertrajectory[i]
self.item.coords((mypts[:2], mypts[2:]))
other.item.coords((otherpts[:2], otherpts[2:]))
self.array.wait(50)
finally:
mypts = mytrajectory[-1]
otherpts = othertrajectory[-1]
self.item.coords((mypts[:2], mypts[2:]))
other.item.coords((otherpts[:2], otherpts[2:]))
self.item.config(fill=myfill)
other.item.config(fill=otherfill)
def compareto(self, other):
myfill = self.item['fill']
otherfill = other.item['fill']
outcome = cmp(self.value, other.value)
if outcome < 0:
myflash = 'white'
otherflash = 'black'
elif outcome > 0:
myflash = 'black'
otherflash = 'white'
else:
myflash = otherflash = 'grey'
try:
self.item.config(fill=myflash)
other.item.config(fill=otherflash)
self.array.wait(500)
finally:
self.item.config(fill=myfill)
other.item.config(fill=otherfill)
return outcome
def position(self):
x1 = (self.index+1)*XGRID - WIDTH//2
x2 = x1+WIDTH
y2 = (self.array.maxvalue+1)*YGRID
y1 = y2 - (self.value)*YGRID
return x1, y1, x2, y2
def nearestindex(self, x):
return int(round(float(x)/XGRID)) - 1
# Subroutines that don't need an object
def steps(here, there):
nsteps = abs(here - there)
if nsteps <= 3:
nsteps = nsteps * 3
elif nsteps <= 5:
nsteps = nsteps * 2
elif nsteps > 10:
nsteps = 10
return nsteps
def interpolate(oldpts, newpts, n):
if len(oldpts) != len(newpts):
raise ValueError("can't interpolate arrays of different length")
pts = [0]*len(oldpts)
res = [tuple(oldpts)]
for i in range(1, n):
for k in range(len(pts)):
pts[k] = oldpts[k] + (newpts[k] - oldpts[k])*i//n
res.append(tuple(pts))
res.append(tuple(newpts))
return res
# Various (un)sorting algorithms
def uniform(array):
size = array.getsize()
array.setdata([(size+1)//2] * size)
array.reset("Uniform data, size %d" % size)
def distinct(array):
size = array.getsize()
array.setdata(range(1, size+1))
array.reset("Distinct data, size %d" % size)
def randomize(array):
array.reset("Randomizing")
n = array.getsize()
for i in range(n):
j = random.randint(0, n-1)
array.swap(i, j)
array.message("Randomized")
def insertionsort(array):
size = array.getsize()
array.reset("Insertion sort")
for i in range(1, size):
j = i-1
while j >= 0:
if array.compare(j, j+1) <= 0:
break
array.swap(j, j+1)
j = j-1
array.message("Sorted")
def selectionsort(array):
size = array.getsize()
array.reset("Selection sort")
try:
for i in range(size):
array.show_partition(i, size)
for j in range(i+1, size):
if array.compare(i, j) > 0:
array.swap(i, j)
array.message("Sorted")
finally:
array.hide_partition()
def bubblesort(array):
size = array.getsize()
array.reset("Bubble sort")
for i in range(size):
for j in range(1, size):
if array.compare(j-1, j) > 0:
array.swap(j-1, j)
array.message("Sorted")
def quicksort(array):
size = array.getsize()
array.reset("Quicksort")
try:
stack = [(0, size)]
while stack:
first, last = stack[-1]
del stack[-1]
array.show_partition(first, last)
if last-first < 5:
array.message("Insertion sort")
for i in range(first+1, last):
j = i-1
while j >= first:
if array.compare(j, j+1) <= 0:
break
array.swap(j, j+1)
j = j-1
continue
array.message("Choosing pivot")
j, i, k = first, (first+last)//2, last-1
if array.compare(k, i) < 0:
array.swap(k, i)
if array.compare(k, j) < 0:
array.swap(k, j)
if array.compare(j, i) < 0:
array.swap(j, i)
pivot = j
array.show_pivot(pivot)
array.message("Pivot at left of partition")
array.wait(1000)
left = first
right = last
while 1:
array.message("Sweep right pointer")
right = right-1
array.show_right(right)
while right > first and array.compare(right, pivot) >= 0:
right = right-1
array.show_right(right)
array.message("Sweep left pointer")
left = left+1
array.show_left(left)
while left < last and array.compare(left, pivot) <= 0:
left = left+1
array.show_left(left)
if left > right:
array.message("End of partition")
break
array.message("Swap items")
array.swap(left, right)
array.message("Swap pivot back")
array.swap(pivot, right)
n1 = right-first
n2 = last-left
if n1 > 1: stack.append((first, right))
if n2 > 1: stack.append((left, last))
array.message("Sorted")
finally:
array.hide_partition()
def demosort(array):
while 1:
for alg in [quicksort, insertionsort, selectionsort, bubblesort]:
randomize(array)
alg(array)
# Sort demo class -- usable as a Grail applet
class SortDemo:
def __init__(self, master, size=15):
self.master = master
self.size = size
self.busy = 0
self.array = Array(self.master)
self.botframe = Frame(master)
self.botframe.pack(side=BOTTOM)
self.botleftframe = Frame(self.botframe)
self.botleftframe.pack(side=LEFT, fill=Y)
self.botrightframe = Frame(self.botframe)
self.botrightframe.pack(side=RIGHT, fill=Y)
self.b_qsort = Button(self.botleftframe,
text="Quicksort", command=self.c_qsort)
self.b_qsort.pack(fill=X)
self.b_isort = Button(self.botleftframe,
text="Insertion sort", command=self.c_isort)
self.b_isort.pack(fill=X)
self.b_ssort = Button(self.botleftframe,
text="Selection sort", command=self.c_ssort)
self.b_ssort.pack(fill=X)
self.b_bsort = Button(self.botleftframe,
text="Bubble sort", command=self.c_bsort)
self.b_bsort.pack(fill=X)
# Terrible hack to overcome limitation of OptionMenu...
class MyIntVar(IntVar):
def __init__(self, master, demo):
self.demo = demo
IntVar.__init__(self, master)
def set(self, value):
IntVar.set(self, value)
if str(value) != '0':
self.demo.resize(value)
self.v_size = MyIntVar(self.master, self)
self.v_size.set(size)
sizes = [1, 2, 3, 4] + range(5, 55, 5)
if self.size not in sizes:
sizes.append(self.size)
sizes.sort()
self.m_size = OptionMenu(self.botleftframe, self.v_size, *sizes)
self.m_size.pack(fill=X)
self.v_speed = StringVar(self.master)
self.v_speed.set("normal")
self.m_speed = OptionMenu(self.botleftframe, self.v_speed,
"single-step", "normal", "fast", "fastest")
self.m_speed.pack(fill=X)
self.b_step = Button(self.botleftframe,
text="Step", command=self.c_step)
self.b_step.pack(fill=X)
self.b_randomize = Button(self.botrightframe,
text="Randomize", command=self.c_randomize)
self.b_randomize.pack(fill=X)
self.b_uniform = Button(self.botrightframe,
text="Uniform", command=self.c_uniform)
self.b_uniform.pack(fill=X)
self.b_distinct = Button(self.botrightframe,
text="Distinct", command=self.c_distinct)
self.b_distinct.pack(fill=X)
self.b_demo = Button(self.botrightframe,
text="Demo", command=self.c_demo)
self.b_demo.pack(fill=X)
self.b_cancel = Button(self.botrightframe,
text="Cancel", command=self.c_cancel)
self.b_cancel.pack(fill=X)
self.b_cancel.config(state=DISABLED)
self.b_quit = Button(self.botrightframe,
text="Quit", command=self.c_quit)
self.b_quit.pack(fill=X)
def resize(self, newsize):
if self.busy:
self.master.bell()
return
self.size = newsize
self.array.setdata(range(1, self.size+1))
def c_qsort(self):
self.run(quicksort)
def c_isort(self):
self.run(insertionsort)
def c_ssort(self):
self.run(selectionsort)
def c_bsort(self):
self.run(bubblesort)
def c_demo(self):
self.run(demosort)
def c_randomize(self):
self.run(randomize)
def c_uniform(self):
self.run(uniform)
def c_distinct(self):
self.run(distinct)
def run(self, func):
if self.busy:
self.master.bell()
return
self.busy = 1
self.array.setspeed(self.v_speed.get())
self.b_cancel.config(state=NORMAL)
try:
func(self.array)
except Array.Cancelled:
pass
self.b_cancel.config(state=DISABLED)
self.busy = 0
def c_cancel(self):
if not self.busy:
self.master.bell()
return
self.array.cancel()
def c_step(self):
if not self.busy:
self.master.bell()
return
self.v_speed.set("single-step")
self.array.setspeed("single-step")
self.array.step()
def c_quit(self):
if self.busy:
self.array.cancel()
self.master.after_idle(self.master.quit)
# Main program -- for stand-alone operation outside Grail
def main():
root = Tk()
demo = SortDemo(root)
root.protocol('WM_DELETE_WINDOW', demo.c_quit)
root.mainloop()
if __name__ == '__main__':
main()
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