87 lines
2.1 KiB
Python
87 lines
2.1 KiB
Python
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# Runestone.Academy thinkcspy course
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# Chapter 8
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# Lab
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import turtle
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border = 10
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def writeData(tt, itr, height):
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tt.goto(0-border, 0-border)
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tt.up()
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if height >= 100:
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tt.left(90)
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tt.forward(height+20)
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tt.right(90)
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tt.forward(itr*39)
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tt.write(str(height), move=False, align='center', font=('Times New Roman', 30, 'normal'))
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tt.forward(70)
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tt.write(str(itr), move=False, align='center', font=('Times New Roman', 30, 'normal'))
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else: # this is here so the last bar actually fills
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tt.left(90)
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tt.forward(height)
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tt.right(90)
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tt.forward(itr*40)
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tt.right(90)
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tt.forward(height)
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tt.left(90)
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def drawBar(t, height):
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""" Get turtle t to draw one bar, of height. """
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t.begin_fill() # start filling this shape
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t.left(90)
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t.forward(height)
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t.right(90)
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t.forward(40)
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t.right(90)
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t.forward(height)
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t.left(90)
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t.end_fill() # stop filling this shape
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def seq3np1(n):
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""" Print the 3n+1 sequence from n, terminating when it reaches 1."""
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count = 1
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while n != 1:
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count += 1
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#print(n)
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if n % 2 == 0: # n is even
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n = n // 2
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else: # n is odd
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n = n * 3 + 1
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#print(n) # the last print is 1
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#print(count)
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return count
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wn = turtle.Screen() # Set up the window and its attributes
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wn.setworldcoordinates(0-border, 0-border, 40*50+border, 150)
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wn.bgcolor("lightblue")
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wn.tracer(100)
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tess = turtle.Turtle() # create tess and set some attributes
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tess.color("purple")
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tess.fillcolor("magenta")
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tess.pensize(3)
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alex = turtle.Turtle()
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alex.color("purple")
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maxSoFar = 0
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for i in range(50):
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start = i + 1
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result = seq3np1(start)
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#print("Number of iterations to get to '1' from", start, ":", result)
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drawBar(tess, result)
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writeData(alex, start, result)
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if result > maxSoFar:
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maxSoFar = result
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print("The max number of iterations was", maxSoFar, "from sequence start", start)
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