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We
use an event-driven
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simulation
to move the
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sweepline
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Events
are
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Segment
start
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When
we first encounter a
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segment
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Segment
end
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When
we reach the
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segments
other endpoint
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Intersect
segments
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When
we reach a segment
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intersection
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Some
of the events, we
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know
ahead of time
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Segment
start
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Segment
end
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If
we knew all events ahead
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of
time we could sort them
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and
do without a Priority
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Queue,
but we dont...
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For segment intersection, we
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have
to determine these
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events
as we move the
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sweepline,
so we need a PQ
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