12 KiB
title | TARGET DECK | FILE TAGS | tags | |
---|---|---|---|---|
Floors & Ceilings | Obsidian::STEM | algebra algorithm |
|
Overview
The floor of x
is the greatest integer less than x
. The ceiling of x
is the least integer greater than x
. These values are denoted \lfloor x \rfloor
and \lceil x \rceil
respectively.
%%ANKI
Basic
How is the floor of x
denoted?
Back: \lfloor x \rfloor
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
%%ANKI
Basic
What is the floor of x
?
Back: The greatest integer less than or equal to x
.
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
%%ANKI
Basic
How is the ceiling of x
denoted?
Back: \lceil x \rceil
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
%%ANKI
Basic
What is the ceiling of x
?
Back: The least integer greater than or equal to x
.
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
%%ANKI
Basic
When does \lfloor x / 2 \rfloor = \lceil x / 2 \rceil
?
Back: When x
is even.
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
%%ANKI
Basic
When does \lfloor x / 2 \rfloor \neq \lceil x / 2 \rceil
?
Back: When x
is odd.
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
%%ANKI
Basic
What does \lceil x \rceil - \lfloor x \rceil
equal?
Back: Either 0
or 1
.
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
%%ANKI
Basic
What can be said about x
if \lceil x \rceil - \lfloor x \rfloor = 0
?
Back: x
is even.
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
%%ANKI
Basic
What can be said about x
if \lceil x \rceil - \lfloor x \rfloor = 1
?
Back: x
is odd.
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
%%ANKI Basic What C operator corresponds to floor division? Back: None. Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
%%ANKI
Basic
When does C operator /
behave like floor division?
Back: When the result is a nonnegative value.
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
%%ANKI
Basic
When does C operator /
behave like ceiling division?
Back: When the result is a nonpositive value.
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
%%ANKI Basic What C operator corresponds to ceiling division? Back: None. Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
%%ANKI
Basic
How does C evaluate 10 / 3
?
Back: 3
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
Tags: c17
END%%
%%ANKI
Basic
How does C evaluate floor(10.f / 3)
?
Back: 3
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
Tags: c17
END%%
%%ANKI
Basic
How does C evaluate ceil(10.f / 3)
?
Back: 4
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
Tags: c17
END%%
%%ANKI
Basic
How does C evaluate -10 / 3
?
Back: -3
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
Tags: c17
END%%
%%ANKI
Basic
How does C evaluate floor(-10.f / 3)
?
Back: -4
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
Tags: c17
END%%
%%ANKI
Basic
How does C evaluate ceil(-10.f / 3)
?
Back: -3
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
Tags: c17
END%%
%%ANKI
Basic
Given r = \lfloor (p + q) / 2 \rfloor
, fair partitioning requires A[r]
to be included in which of A[p..r-1]
or A[r+1..q]
?
Back: A[p..r-1]
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
%%ANKI
Basic
Given r = \lfloor (p + q) / 2 \rfloor
, when is A[p..r]
or A[r+1..q]
equally sized?
Back: When A[p..q]
has even size.
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
%%ANKI
Basic
Given r = \lceil (p + q) / 2 \rceil
, fair partitioning requires A[r]
to be included in which of A[p..r-1]
or A[r+1..q]
?
Back: A[r+1..q]
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
%%ANKI
Basic
If A[p..q]
has odd size, what r
most fairly allows partitions A[p..r]
and A[r+1..q]
?
Back: r = (p + q) / 2
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
%%ANKI
Basic
If A[p..q]
has odd size, what r
most fairly allows partitions A[p..r-1]
and A[r..q]
?
Back: r = (p + q) / 2
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
%%ANKI
Basic
If A[p..q]
has odd size, what r
ensures A[p..r-1]
has same size as A[r+1..q]
?
Back: r = (p + q) / 2
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
%%ANKI
Basic
If A[p..q]
has even size, what r
most fairly allows partitions A[p..r]
and A[r+1..q]
?
Back: r = \lfloor (p + q) / 2 \rfloor
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
%%ANKI
Basic
If A[p..q]
has even size, what r
most fairly allows partitions A[p..r-1]
and A[r..q]
?
Back: r = \lceil (p + q) / 2 \rceil
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
%%ANKI
Basic
Given A[p..q]
and r = \lfloor (p + q) / 2 \rfloor
, how does the size of A[p..r]
compare to A[r+1..q]
?
Back: It either has zero or one more members.
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
%%ANKI
Basic
Given A[p..q]
and r = \lfloor (p + q) / 2 \rfloor
, what is the size of A[p..r]
in terms of n = q - p + 1
?
Back: \lceil n / 2 \rceil
.
Reference: Thomas H. Cormen et al., Introduction to Algorithms, 3rd ed (Cambridge, Mass: MIT Press, 2009).
END%%
%%ANKI
Basic
Given A[p..q]
and r = \lfloor (p + q) / 2 \rfloor
, what is the size of A[r+1..q]
in terms of n = q - p + 1
?
Back: \lfloor n / 2 \rfloor
.
Reference: Thomas H. Cormen et al., Introduction to Algorithms, 3rd ed (Cambridge, Mass: MIT Press, 2009).
END%%
%%ANKI
Basic
Given A[p..q]
and r = \lceil (p + q) / 2 \rceil
, how does the size of A[p..r-1]
compare to A[r..q]
?
Back: It either has zero or one fewer members.
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
%%ANKI
Basic
Given A[p..q]
and r = \lceil (p + q) / 2 \rceil
, what is the size of A[r..q]
in terms of n = q - p + 1
?
Back: \lceil n / 2 \rceil
.
Reference: Thomas H. Cormen et al., Introduction to Algorithms, 3rd ed (Cambridge, Mass: MIT Press, 2009).
END%%
%%ANKI
Basic
Given A[p..q]
and r = \lceil (p + q) / 2 \rceil
, what is the size of A[p..r-1]
in terms of n = q - p + 1
?
Back: \lfloor n / 2 \rfloor
.
Reference: Thomas H. Cormen et al., Introduction to Algorithms, 3rd ed (Cambridge, Mass: MIT Press, 2009).
END%%
%%ANKI
Basic
Given A[p..q]
and r = \lfloor (p + q) / 2 \rfloor
, how does the size of A[p..r-1]
compare to A[r..q]
?
Back: It either has one or two fewer members.
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
%%ANKI
Basic
Given A[p..q]
and r = \lceil (p + q) / 2 \rceil
, how does the size of A[p..r]
compare to A[r+1..q]
?
Back: It either has one or two more members.
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
%%ANKI
Basic
Given A[p..q]
and r = \lfloor (p + q) / 2 \rfloor
, why is the size of A[p..r]
potentially larger than A[r+1..q]
?
Back: If A[p..q]
has odd size, A[p..r]
contains the midpoint.
Reference: Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
END%%
References
- Ronald L. Graham, Donald Ervin Knuth, and Oren Patashnik, Concrete Mathematics: A Foundation for Computer Science, 2nd ed (Reading, Mass: Addison-Wesley, 1994).
- Thomas H. Cormen et al., Introduction to Algorithms, 3rd ed (Cambridge, Mass: MIT Press, 2009).