20. Tightrope
A square changes color as you balance between two circles.
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There are two unmoving blue circles on the screen.
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You can move a square with the mouse.
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Square color is:
- Green if the distance from the square to circle 1 and the distance from the square to circle 2 are within 20 of each other.
- Red otherwise.
Some people had trouble understanding this description. In a computer-like language:
a = distance from square to circle 1
b = distance from square to circle 2
green if a and b are within 20 of each other
Write:
- Model
- The function
square-color: model -> color.