Answered a different question (the one posted on the outline as opposed
to the one given in class).
To look up a phone number:
1. Go to the section of the phone book that lists names starting with the same
letter as the name you are using.
2. Find the part of this section that lists names with the same second letter
as the name you are using.
3. Continue matching up each subsequent letter until there are no more letters
left and you have found a match.
4. If you have found a name which matches the one you were looking for
exactly, the number attached to it may be the one you are looking for.
To look up a name:
1. Find a reverse directory.
2. Go to the section of the phone book that lists numbers starting with the
same number as the one you are using.
3. Find the part of this section that lists numbers with the same second
number as the one you are using.
4. Continue matching up each subsequent number until there are no more numbers
left and you have found a match.
5. If you have found a number which matches the one you were looking for
exactly, the name attached to it is the one you are looking for.
(Note: there are easier ways to do these -- i.e. call information, type the
name/number into certain web sites, or "*69" -- but I assumed that this was
what you were looking for.)
Ho to look up a phone # by name in the phone book.
(assuming the person can distinguish between first and last names and knows
- 1) locate the first letter of the last name.
- 2) find the corresponding section in the phone book.
- 3) locate the second letter of the last name.
- 4) find the corresponding section in the phone book.
- 5) locate the next letter in the last name.
- 6) repeat steps 5 and then 4 until the last name has been located.
- 7) if there is more than one entry for the last name, determine the first
- 8) locate the first letter of the first name and see if there are any matches
within the entries for the last name.
- 9) if there is more than one match, locate the next letter in the first name,
match it to listed entries. proceed until there is only one match.
- 10) the number will be listed in the same row as the name, usually in the
to the right.
How to look up a name by a phone #.
(as far as i know, there is no efficient way to do this using a physical phone
- 1) open the phone book. start at the first listing for numbers.
- 2) scan through all numbers, going down column by column until you have found
- 3) good
Algorithm for finding a number for a name in a phone book:
- 1. Remember the name, last name first, first name last, and the appropriate
- 2. Using the first letter of the last name, locate the appropriate
alphabetical section in which the name should appear.
- 3. Using the second letter of the last name, find the subsection of first and
second letters combined, in the appropriate order, in which the name should
appear. (If the last name consists of only two letters, find the appropriate
- 4. Using the third letter, find the possible names in a subsection of the
first three letters in the correct order. Continue this step with x+1 letters
of the name until you have a subsection of names exactly matching the last
name of the person whose number you are trying to locate. (x is the number of
letters used in the previous step, consistently.) If there is only one of the
last name, (check for duplicates) identify the number, and return phone number
- 5. Begin the second step using the first letter of the first name, but limit
the section to only those exactly matching the last name. Continue to step 4,
again focusing on the first name only within the set of exactly matching last
- 6. When both first and last name match the name you are locating, check for
duplicates. IF there are no duplicates, return phone number information.
Algorithm for finding a name from a number in a phone book:
- 1. Identify and remember the number for the name you want to find. Remember
the area marker at the beginning of a phone number and the four digits
- 2. Begin checking in the front page of listed numbers in the phone book. If
the area marker matches, then and only then [check for the remaining four
digits in correct order.]
- A. Only looking at those numbers with the correct area marker, check for the
first digit in the four.
- B. Each time you find a first digit match, check for the second digit match.
If it does not match, return to A beginning with the next number on the list.
- C. If it does match, check for the third digit match. If it does not match,
return to A beginning with the next number on the list.
- D. If it does match, check for the fourth digit match. If it does not match,
return to A beginning with the next number on the list.
- E. IF it does match, return the name information for the located number, and
Assuming you know what alphabetical order means, given a phone book and a
- 1. Alphabetically look up the person's last name in the phone book.
- 2. Once you've looked up the person's last name, locate the person's first
name alphabetically within that listing of last names (e.g. if the person's
last name is willis, look alphabetically within the 'willis' listings for
their first name).
- 3. Once you've located their full name, follow the dotted line straight across
to the right to locate the phone number.
Given a phone book, a phone number and no name:
I don't know that there's any way to realistically locate the person to whom
the number belongs. Essentially, to find it's owner, you'd have to just start
scanning down the phone numbers until you found a match. Hugely inefficient
and time-consuming, and that's assuming the number is even listed.
Given a name describe how to determine a telephone number
- 1.) Identify first letter in name
- 2.) Turn to the page(s) of the identified letter in the phone book.
- 3.) The section of the phone book which contains the identified letter as the first letter now comprises the entire
domain in which future searches will occur
- 4.) Identify the second letter in the name
- 5.) Repeat step two
- 6.) The section of the phone book which contains the first identified letter first and the second identified letter
second now comprises the entire domain in which future searches will occur
- 1.) Identify the n1 (first letter) letter in the name
- 2.) Turn to page(s) of the identified letter in the phone book
- 3.) The section of the phone book which contains n1 now comprises the entire domain in which future searches will
- 4.) If there are remaining letters, then continue process for letter n(x+1) where x the number of previous searches
Given a phone number describe how to determine a name
- 1.) Begin at the beginning of the phone book
- 2.) Locate next number which has not been previously compared
- 3.) If known number does not match number, then locate next number and begin at step two or if known number does match number, then return name of matching number
Describe the how to put names and corresponding phone numbers in
a phone book alphebetically.
- 1. Enter everyone's name (last name first) along with their corresponding
- 2. Somehow make sure that each person's phone number stays attached to the
correct name at all times, no matter where it is moved to (I'm not sure how to
- 3. Assign the first letter through the last letter in each person's full name
(last name first) to a corresponding number (e.g. A = 1, B = 2, ...).
- 4. Put the numbers (i.e. the letters) in order from smallest to greatest,
starting with the first letter in the person's last name and going to the last
letter in the person's first name.
- 5. If two numbers are the same for first letter, then you need to go to the
next letter, and continue until the numbers (letters) are different.
- 6. Continue this process until all the numbers are in order from smallest to
largest, and therefore, putting the names (and phone numbers) in alphabetical
1. People's names are generally arranged in phone books in alphabetical order
by the last name of the person. The first name of the person is listed after
the last name so that people of the same last name can be differentiated.
Arrange the name in question in that manner, with the last name first and the
first name last.
2. Phone books have index names at the top of each page to make the
identifying of one name easier. Go to the first page with indices which have
the same first letter of the last name as that of the name in question.
3. Within the range of this first letter, go to the first page with the
second letter of the subject's last name. Continue doing this with each
successive letter of the person's name, until you have arrived at a name
identical to that of the one for which you are searching.
4. Write down the number associated with the name you have found.
5. In the event of multiple people with the same name, it may be necessary to
call each of the multiple numbers to discover which is the person for whom you
With the number.
1. Phone books are NOT put in numerical order by phone number.
2. Write down your number so that it is easy to compare (and hard to forget)
3. Beginning with the first page of phone listings, compare every number in
the phone book with that you have written until a number is found which is an
4. Write down the name of the person with whom the number is associated.
5. Multiple people should not have the same number.
To find number g given name x:
- 1.For each listing (name, phone number) in the book,
- if x=name, return phone number.
- otherwise, discard name and repeat step 1.
To find name x given number g:
- 1. For each listing (name, phone number) in the book,
- if g=phone number, return name.
- otherwise, discard phone number and repeat step 1.
How to look up a phone number if you have a name:
Since this is the purpose for which a phone book is designed, this task
is not extremely difficult.
- 1. Accquire a phonebook for the area where the designated number's owner
resides. Use the "White Pages" section, as this is the residential
section and is organized alphabetically.
- 2. Using the persons last name, locate the section of the phone book
that alphabetically correspnds (i.e. if their name is Smith, turn to the
- 3. Locate their last name in the book, first by the first letter, then
using the ensuing letters to narrow the search down (Smith> Sm-, Smi-, etc).
- 4. If there are repeat last names, consult their first name to narrow
the search. If there are repeat first names, consult their middle initial
- 5. If the name you have singled out is in accordance to the address you have,
and if the right person picks up the phone when you call, you have
used a phone book.
How to look up a name if you have a number:
A decidedly harder process, considering that this is not the intended way
of using a phonebook.
- 1. This is going to be a length process of elimination. First narrow the
search as much as initially possible. Using the area code (the first 3
determine the general location of the owner of the number. Get the
appropriate phone book.
- 2. Note the first digit in the local number (the last 7 digits). Going
through the book page by page, highlight all of the numbers that share this
digit. Eliminate the rest.
- 3. Note the second digit of the number and repeat step two, eliminating
the phone numbers that do not have the designated second digit.
- 4. Continue this process, going digit by digit, until the matching numbe
remains. the number has now been located.
...or maybe try starting with the last digit and working backwards. The
first one or two digits are more likely to be shared, so they are more easily