72 lines
3.0 KiB
Python
72 lines
3.0 KiB
Python
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from manim import *
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config.background_color = (33, 33, 33)
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class FactorialTree(Scene):
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# This animation is fundamentally wrong, as it does NOT utilize this type of graph correctly
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# Still gets the job done though (I think)
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def construct(self):
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# Draw the initial node
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self.bottom = Text(f"factorial(5)", font_size=24, font="Agave Nerd Font Mono").to_edge(DOWN)
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self.play(Write(self.bottom))
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self.top_num = 1
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self.top = Text(f"result = 0", font_size=24, font="Agave Nerd Font Mono").to_edge(UP).to_edge(LEFT)
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self.last_node = None
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self.play(Write(self.top))
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root = self.create_node("5!", position=ORIGIN).to_edge(UP)
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self.play(FadeIn(root))
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def drawNode(node, parent, position, right = False):
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# Draw a multiplication sign in the center between the left and the right node
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self.bottom.become(Text(f"factorial({n})", font_size=24, font="Agave Nerd Font Mono").to_edge(DOWN))
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self.play(Indicate(self.bottom))
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self.play(GrowArrow(Arrow(parent.get_bottom(), node.get_top()).scale(0.5)))
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if final:
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self.play(Write(Text("x", font_size=24, font="Agave Nerd Font Mono").move_to(position + DOWN * 0.5)))
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self.last_node = node
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self.play(FadeIn(node))
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self.play(FadeToColor(node, GREEN))
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# Recursive function to create tree
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def factorialTree(n, parent, position, level=1):
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if n <= 0:
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# Closing animation
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self.play(FadeToColor(parent, GREEN))
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self.bottom.become(Text(f"factorial({n})", font_size=24, font="Agave Nerd Font Mono").to_edge(DOWN))
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self.play(Indicate(self.bottom))
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return
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# Left child (n-1)!
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left_pos = position + LEFT + level * DOWN
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left_child = self.create_node(f"{n-1}!", position=left_pos)
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drawNode(left_child, parent, position)
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factorial_tree(n-1, left_child, left_pos, level + 0.3)
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# Funky updates
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self.top_num *= n
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self.play(FadeToColor(parent, GREEN))
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# Right child (result of n-1 factorial)
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right_pos = position + RIGHT + level * DOWN
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right_child = self.create_node(str(self.top_num), position=right_pos)
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drawNode(right_child, parent, position, final=True, last=True)
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self.play(Transform(self.top, Text(f"result = {self.top_num}", font_size=24, font="Agave Nerd Font Mono").to_edge(UP).to_edge(LEFT)))
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# Create the tree
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factorial_tree(5, root, root.get_center())
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self.play(Indicate(self.last_node))
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self.wait(1)
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def create_node(self, content, position):
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node = Circle().scale(0.25)
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node_text = Text(content).scale(0.25).move_to(node)
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node_group = VGroup(node, node_text).move_to(position)
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return node_group
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