For each of the following Unix system calls, give a condition that causes it to fail: open, read, fork, execve, unlink.
In: Computer Science
create overloaded functions called lastValue. The first function should take as a parameter a string and the second function should take as a parameter an int. each of you functions should return an int value. in the case of the function that takes the string as an argument you will return the ascii value of the last character in the string. in the case of the function that takes an int parameter your function will return the last digit in the number c++
In: Computer Science
1. Write a program that computes the smallest and largest of a set of values that are stored in an array. Ask the user for the set size (and hence the array size). Populate the array with user input. (Java language)
In: Computer Science
FOR JAVA
Define a class QuadraticExpression that represents the quadratic expression ax^2 + bx + c: You should provide the following methods (1) default constructor which initalizes all the coefficients to 0 (2) a constructor that takes three parameters public QuadraticExpression(double a, double b, double c) (3) a toString() method that returns the expression as a string. (4) evaluate method that returns the value of the expression at x public double evaluate(double x) (5) set method of a, b, c public void setA(double newA) public void setB(double newB) public void setC(double newC) (6) public static QuadraticExpression sum( QuadraticExpression q1, QuadraticExpression q2): returns a new expression that is the sum of the q1 and q2 (7) public static QuadraticExpression scale( double r, QuadraticExpression q) returns a new expression that is r times q (8) public int numberOfRoots() returns number of roots, where 3 means infite number of roots (9) public void add( QuadraticExpression q) add q to the calling expression object (10) public double smallerRoot() throws Exception Depending on the equation ax^2 + bx + c = 0: if no roots, throw exception if single root, return it if two roots, return the smaller root if infinite root, return -Double.MAX_VALUE (11) public double largerRoot() throws Exception if no roots, throw exception if single root, return it if two roots, return the larger root if infinite root, return Double.MAX_VALUE (12) equals method This should OVERRIDE equals method from Object class return true if two expressions have same a, same b and same c (13) clone return a copy of the calling object (14) use javadoc style comments for the class, and the methods At minimum, include the author, parameters and return types for each method. (15) use javadoc to generate document for your class (16) test your class: you can write your own main to test your code; but you have to pass the test in QuadraticExpressionTest.java (17) submit a. QuadraticExpression.java b. QuadraticExpression.html on blackboard. (18) turn in printout of a. QuadraticExpression.java b. the output of your program
Please!! test before posting it
In: Computer Science
Consider the following schema:
Suppliers(sid: integer, sname: string, address: string)
Parts(pid: integer, pname: string, color: string)
Catalog(sid: integer, pid: integer, cost: real)
The key fields are underlined, and the domain of each field is listed after the field name. Therefore sid is the key for Suppliers, pid is the key for Parts, and sid and pid together form the key for Catalog. The Catalog relation lists the prices charged for parts by Suppliers.
WRITE THE FOLLOWING QUERIES IN RELATIONAL ALGEBRA WITH BASIC OPERATORS AND AGGREGATE FUNCTIONS ONLY
MEANS IF THE QUERIES CANNOT FULLY EXPRESSED BY BASIC OPERATORS, USE AGGREGATES.
1. Find the names of suppliers who supply some red part.
2. Find the sids of suppliers who supply some red or green part.
3. Find the sids of suppliers who supply some red part or are at 221 Packer Street.
4. Find the sids of suppliers who supply some red part and some green part.
5. Find the sids of suppliers who supply every part.
6. Find the sids of suppliers who supply every red part.
7. Find the sids of suppliers who supply every red or green part.
8. Find the sids of suppliers who supply every red part or supply every green part.
9. Find pairs of sids such that the supplier with the first sid charges more for some part than the supplier with the second sid.
10. Find the pids of parts supplied by at least two different suppliers.
11. Find the pids of the most expensive parts supplied by suppliers named Yosemite Sham.
12. Find the pids of parts supplied by every supplier at less than $200. (If any supplier either does not supply the part or charges more than $200 for it, the part is not selected.)
In: Computer Science
MySQL
Multiple Choice
Answer as soon as possible
1. Which one of the following is
not a Replication Data Format?
(a) Row
(b) Mixed
(c) Statement
(d) Sync
2. When executing the following statement on
the master:
UPDATE enormous_table SET col1 = 0;
Which replication format would be more efficient?
(Assume enormous_table is a large table with millions of
rows)
(a) Statement
(b) Row
(c) Neither
3. When executing the following statement on
the master:
INSERT INTO summary_table(col1, col2, sum_col3)
SELECT col1, col2, sum(col3)
FROM enormous_table
GROUP BY col1, col2;
Which replication format would be more efficient?
(Assume enormous_table is a large table with millions of
rows)
(a) Statement
(b) Row
(c) Neither
4. Which one of the following is a way to
detect if there is an error replicating data on the slave?
(a) Run SHOW MASTER STATUS and Look for an error description in
LAST_SQL_ERROR in the results.
(b) Run SHOW MASTER STATUS and Look for an error description in
INVALID_COMMAND_FOUND in the results.
(c) Run SHOW SLAVE STATUS and Look for an error description in
INVALID_COMMAND_FOUND in the results.
(d) Run SHOW MASTER STATUS and Look for an error description in
SYNCING = NO in the results.
(e) Run SHOW SLAVE STATUS and Look for an error description in
LAST_SQL_ERROR in the results.
5. Which one of the following is the correct
command to skip the next command in the binlog on the slave (this
is sometimes used to skip a command that is causing a replication
error)?
(a) SET GLOBAL SQL_SLAVE_SKIP = YES;
(b) SET GLOBAL SQL_SLAVE_SKIP_COMMANDS = 1;
(c) SET GLOBAL SQL_SLAVE_SKIP_ON_ERROR = YES;
(d) SET GLOBAL SQL_SLAVE_SKIP_COUNTER = 1;
6. Which one of the following is the command
for temporarily disabling the binlog on the master so you can run a
statement without it getting replicated to the slave(s)?
(a) SET REPLICATE_TO_SLAVE = NO;
(b) SET SQL_LOG_BIN = 0;
(c) SET ENABLE_BINLOG = 0;
(d) SET DISABLE_BINLOG = YES;
In: Computer Science
Respond to the following in a minimum of 175 words: Discuss your response to the following: What are some qualitative tools used to analyze data in Microsoft® Excel®? How do these tools assist users with their business decisions? Provide an example from a past or current work experience when the use of these tools would have helped the outcome of your spreadsheet. How was the data analyzed differently? Explain your answer.
In: Computer Science
6) What is the 6-bit 1's complement representation of -1710?
Write your answer in the format 0bXXXX... Where X's are binary digits. Include leading 0's (zeroes).
7) What is the 6-bit sign-magnitude representation of -1710?
Write your answer in the format 0bXXXX... Where X's are binary digits. Include leading 0's (zeroes).
9) What is the 8-bit 1's complement representation of 1710?
Write your answer in the format 0xHHHH... Where H's are hexidecimal digits. Include leading 0's (zeroes). Write hexidecimal digits, A-F, in capitals.
10) What is the 8-bit sign-magnitude representation of 1710?
Write your answer in the format 0xHHHH... Where H's are hexidecimal digits. Include leading 0's (zeroes). Write hexidecimal digits, A-F, in capitals.
In: Computer Science
USE PYTHON ONLY
Zeller’s congruence is an algorithm developed by Christian Zeller to calculate the day of the week. The formula is
h = (q + 26(m+1)//10 + k + k//4 +j//4 +5j) % 7
where
- h is the day of the week (0: Saturday, 1: Sunday, 2: Monday,
3: Tuesday, 4: Wednesday, 5: Thursday, 6: Friday).
- q is the day of the month.
- m is the month (3: March, 4: April, ..., 12: December). January
and February are counted as months 13 and 14 of the previous
year.
- j is year//100.
- k is the year of the century (i.e., year % 100).
Write a program that prompts the user to enter a year, month, and day of the month, and then it displays the name of the day of the week.
In: Computer Science
Write a PHP script to display in frequency all the words in the
submitted paragraph.
Convert the string to an array of words.
Count the number of times the words are used. Hint:
array_count_values($arrayname)
Sort the array in frequency order.
Print the array to the screen. Hint: print_r($arrayname)
In: Computer Science
Visual C# 2017
Write a program named Eggs that declares four variables of type int to hold the number of eggs produced in a month by each of four chickens, and assign a value to each variable.
Sum the eggs, then display the total in dozens and eggs. For example, if the total number of eggs was 95, the output would be 95 eggs is 7 dozen and 11 eggs.
Note: For final submission ensure that the total number eggs equals 127.
In: Computer Science
My code in python keeps failing when the investment is 12 and the market price is 1. I'd like to keep my code, just fix the issue. Thank you.
This is what the automated tests keep saying:
market_price = 1
available_funds = 12
Expected output: Buy 2 shares
Actual output : Hold Shares
We can profit most by buying 2 shares
--------------------------------------------------------------
I'm stopping the tests for now,
because it looks like you still have some work to do.
You should review the test feedback above,
and then work to resolve these issues in your code.
I Ran 7 of 8 test(s).
Your code passed 4 test(s).
Your code failed 3 test(s).
Continue to build on your success,
and focus on creating the simplest code
that will pass just one more test.
Here is my Code:
def trade_action(current_stock, purchase_price, current_price,
investment):
# Write your code here.
if purchase_price>= current_price:
investment-=10
number_shares = investment/current_price
profits= (number_shares*current_price-purchase_price)-10
if profits >= 0:
return number_shares
else:
return "Hold Shares"
elif current_price>= purchase_price:
if current_price-purchase_price*current_stock-10>0:
return "Sell Shares"
else:
return "Hold Shares"
As stated. The problem is when the computer inputs 12 for investment and 1 for market share, the program returns Hold Shares, when it is suppose to return purchase 2 shares.
Project Challenge: Automatic Stock Trader
DIRECTIONS
Many investment management companies are switching from manual stock trading done by humans to automatic stock trading by computers. You've been tasked to write a simple automatic stock trader function that determines whether to buy, sell, or do nothing (hold) for a particular account. It should follow the old saying "Buy low, sell high!"
This function takes 4 input parameters in this order:
Any transaction (buy or sell) costs $10. This $10 must be paid out of the available_funds for a purchase, or out of the proceeds of a stock sale. Be sure to account for this fee in your profit calculations.
A purchase would be considered profitable when the current market price is lower than the purchase price, and the available funds will allow us to buy enough shares so that the difference in value will cover the $10 transaction fee. In this case the function should return the string "Buy # shares" where # is an integer representing the number of shares to purchase.
A sale would be considered profitable when the current market price is higher than the purchase price, and the value gained by selling the shares will cover the $10 transaction fee. In this case the function should return the string "Sell # shares" where # is an integer representing the number of shares to sell.
If neither a buy nor a sell would be profitable, then the function should return the string "Hold shares."
Here are some test cases that your function should satisfy:
Test 1 | Test 2 | Test 3 | Test 4 | Test 5 | Test 6 | |
current_shares | 10 | 20 | 15 | 1 | 10 | 1 |
purchase_price | 100 | 2 | 12 | 1 | 1 | 1 |
market_price | 1 | 1 | 1 | 11 | 3 | 12 |
available_funds | 10 | 21 | 12 | 0 | 30 | 0 |
OUTPUT | Hold shares | Buy 11 shares | Buy 2 shares | HoldShares | Sell 10 shares | Sell 1 shares |
Rationale for test cases:
Test 1
Even though the current market price is very low (compared to the
purchase price), after paying the $10 transaction fee, we would not
have any funds left to buy shares; so we can only hold.
Test 2
After paying the $10 transaction fee, there are enough funds
remaining to buy 11 shares. At a purchase_price vs. market_price
difference of $1 per share, our 11 shares represent a value gain of
$11 dollars, which is $1 more than the $10 transaction fee - so we
come out $1 ahead.
Test 3
After paying the $10 transaction fee, there are enough funds
remaining to buy 2 shares. At a purchase_price vs. market_price
difference of $11 per share, our 2 shares represent a value gain of
$22 dollars, which is $12 more than the $10 transaction fee - so we
come out $12 ahead.
Test 4
Selling our 1 share for $11 will leave us with just $1 after we pay
the $10 transaction fee. That is the same as what we paid for it,
and we won't make any profit - so we should hold.
Test 5
With a market_price vs. purchase_price vs. difference of $2 per
share, we stand to make $20 from the sale of our 10 shares. This is
$10 more than the price of the transaction fee, so we will come out
$10 ahead - therefore we should sell all 10 shares.
Test 6
Our 1 share is worth $11 more than we paid for it at the current
market price. The $11 dollars obtained by selling that share now
will still leave us with a profit of $1 after paying the $10
transaction fee. Profit is profit, so we should sell.
Things to think about when you’re designing and writing this program:
In: Computer Science
1. Write a program that computes the smallest and largest of a set of values that are stored in an array. Ask the user for the set size (and hence the array size). Populate the array with user input.
In: Computer Science
1. If an attacker sends a large number of probe packets via IPv4, you can block them by blocking the attacker’s IP address. Now suppose the attacker uses IPv6 to launch the probes; for each probe, the attacker changes the low-order 64 bits of the address. Can these probes be blocked efficiently? If so, what do you have to block? Might you also be blocking other users? 2. Suppose someone tried to implement ping6 so that, if the address was a link-local address and no interface was specified, the ICMPv6 Echo Request was sent out all non-loopback interfaces. Could the end result be different than conventional ping6 with the correct interface supplied? If so, how likely is this?
In: Computer Science
In: Computer Science