Reference no: EM133353326

Question 1 Use SQL

There is a blood bank which maintains two tables; DONOR that contains information on the people who are willing to donate blood and ACCEPTOR, the people who are in need of blood. The bank wants to conduct a survey and find out the city that has the best and the worst donor sum amount/accepter sum amount ratio. Both ratios are unique. That is, exactly one city has worse ratio.

The donor sum amount is the total amount of blood, regardless of blood group, that people are ready to donate. The acceptor sum amount is the total amount of blood needed by that city.

There must be exactly two rows that donate the best and the worst ratios. The order of the rows does not matter.
Each row must contain the following attributes.
1. The city's name (CITY)
2. The ratio (donor sum / acceptor sum amount) corrects to 4 decimal places

The schema of two tables is given below:

Donor
Name	Type	Description
ID	integer	It is the id of the donor
Name	String	It is the name of the donor
Gender	Character	It is the gender of the donor
city	string	It is the city where the donor lives
BLOOD_GROUP	String	It is the blood group of the donor
AMOUNT	Integer	It is the amount of blood in pints, which the donator can donate

Acceptor
Name	Type	Description
ID	integer	It is the id of the Acceptor
Name	String	It is the name of the Acceptor
Gender	Character	It is the gender of the Acceptor
city	string	It is the city where the Acceptor lives
BLOOD_GROUP	String	It is the blood group of the Acceptor

ACCEPTER
ID	NAME	GENDER	CITY	BLOOD_GROUP	AMOUNT
1	LINDA	F	Warne, NH	A+	9
2	CHARLES	M	Warne, NH	AB+	8
3	RICHARD	M	East Natchitoches, PA	AB+	3
4	LINDA	F	East Natchitoches, PA	A+	1
5	PATRICIA	F	Warne, NH	A+	5

Question 2 Please us Python or other language
Delete Nodes Greater Than X > coding Easy List Data structure algorithm problem solving

Question description
Given a singly link list and an integer, x, remove nodes greater than x
Example:
List = 100 -> 105 -> 50
X = 100
List becomes 100 -> 50
Return a reference to the root node of the list after removing 105
Function Description
Complete the function removeNodes in the editor below the function must return a reference to the root node of the final list.
removeNodes has the following parameter(s);
node listHead: a reference to the root node of the singly-linked list
int x: integer, the maximum value to be included in the return singly-linked list
Return a reference to the root node of the list

Constraints
• 1 <= n, x <= 10^5
• 1 <=SinglylinkedListNode values <= 10^5

Input format for custom testing
Input from stdin will be processed as follows and passed to the function
The first line contains an integer n, the number of nodes in the linked list
The next n lines each contain an element to insert into the linked list
The last line contains x, the maximum value allowable in the link list

Question 3 Please use python for this question.
Customer support for an e-commerce business uses a computerized algorithm for evaluation if support tickets are still open. Open and closed tickets are represented by different by different open and closed braces respectively. For example, each of the braces '( [ { represent an open ticket and need matching braces }])' in that order to close them.
The braces in a string are balanced if the following conditions are met.
• All open braces must be closed
• Each closed braces must have a matching open brace
• Any set of nested braces must be closed before its surrounding braces

Given a 2-dimentiaonal array of strings comprised of braces, verify that the braces in each string are balanced.
Return ‘YES' if the braces are balanced and ‘NO' otherwise
Example
Braces = [‘[{}]', ‘[{]}']
• The braces in the first string ‘[{}]' are balanced, because all braces are closed and all nested are closed in order.
• The braces in the second string ‘[{]}' are not balanced, because the nested brace "{ was not closed before its surrounding "[ ]', so the order was not respected.
• The result is [‘Yes', ‘NO']
Function description matchBraces in the editor below
matchingBraces has the following parameter(s);
string braces[n]; an array of strings to analyze
returns:
string[]; an array of strings, either ‘YES' or ‘NO' where the string at each index i denotes whether the braces are balanced[i].
Constraints
• 1 <= n <=15
• 1 <= length of each braces [i] <= 100
• Each braces[i] consists of (, ), {, }, [ and ] only,
Input format for custom testing
Input from stdin will be processed as follows and passed to the function
The first line contains an integer n, the number of elements in braces.
Each of the next n lines contains a string that describes braces[i] where 0 <=i< n
Sample input
STDIN Function
-------- -----------
2 ---> braces [ ]size n =2
[} [ ] ( ) --> braces = [ ‘ { } [ ] ( ) ‘ , ‘{ [ } ] } ‘ ]
{ [ } ] }
Sample Output
YES
NO
Explanation
• The braces in the first string ‘{} [] ()' are balanced, because all braces are closed.

Question 4 Used python for this or other language.
Build a computer simulation or a mobile robot. The robot moves on an infinite plane, starting from position (0, 0), its movements are described by a command string consisting of one or more of the following three letters
• G instructs the robot to move forward one step.
• L instructs the robot to turn left in place
• R instructs the robot to turn right in place
The robot performs the instruction in command sequence in an infinite loop. Determine whether there exists some circle such that the robot always moves within the circle.
Consider the commands R and G executed infinitely. A diagram of the robot's movement looks like;
RG ---> RG,

RG <---- RG
The robot will never leave the circle.
Function description
Complete the function doesCircleExist in the editor below. The function must return an array of n strings either YES or NO based on whether the robot is bound within the circle or not. In order of test results.

doesCircleExist has the following parameter(s);
commands[commands[0]...commands[n-1]]: An array of n commands[1] where each represents a list of commands to test.

Constraints
• 1 <= |commands[i]| <= 2500
• 1 <= n <= 10
• Each command consists of G, L, and R only
Input format for custom testing
Input from Stdin will be processed as follows and passed to the function.
The first line contains an integer n,the number of elements in commands.
The next n lines each contain a string describing commands[i] where 0 <= I < n.
Sample Case 0
3
G
L
RGRG

Sample output
If they are in the circle
NO
YES
YES
Explanation 1
Consider the robot's initial orientation to be facing north toward the positive y direction. The robot performs the following four steps in a loop:
1. Go forward one step. The robot moves from (0, 0) to (0, 1).
2. Turn right. The robot turns eastward, facing the positive x direction.
3. Go forward one step. The robot moves from (0, 1) to (1, 1).
4. Turn left. The robot turns northward, facing the positive y direction again.

RG -----> LG

RG ----> LG

G
The robots than repeats these steps infinitely, following an endless zig-zag path in the north-easterly direction. Because the robot will never turn in such a way it would be restricted to a circle. Set index 0 of the return array to NO.
Hint 1
If it is not required to perform the commands infinitely. Performing the commands 4 times in a row is sufficient to check if it forms a circle.
Hint 2
Duplicate the command 4 times and start from (0, 0). Update the x and y coordinates based on the particular instruction (‘L', ‘R' or ‘G'), if the final coordinates is again (0, 0) it forms a circle

Question 5. Use SQL

There is a database that contains a website's traffic data over a period of 30 days. The first table contains user's information including the user type (user, crawler, admin). The second table consists of the time of each visit to the website, the id of the visitor, time spent on the website for users.user_type = ‘user'.
Note: avg time spent must have 4 decimals digits and rounded off(example: 5/3 = 16667, 5/2 = 2.5000 and 1/3 = 0.3333)

Schema
There are two tables : users, traffic

Users
Name	Type	Description
Id	INTEGER	The user's unique id, it is the primary key

Name	VARCHAR	his is the second column and the name of the user
User_type	VARCHAR	Type of user

Traffic
Name	Type	description
User_id	INTEGER	Id of the user from the users table
Visited_on	DATE	Date on which the user visited the website
Time_spent	INTEGER	Time spent on website in seconds

Sample Data tables

USERS
Id	Name	User_type
1	Matt	user
2	John	user
3	Louis	admin

Traffic
Id	Type	description
1	2019-03-01	15
2	2019-03-02	20
3	2019-03-03	10

Sample output
Visited_onavg_time_spent
2019-03-01 15.0000
2019-03-02 17.0000
2019-03-03 15.0000
Expalnation
Row 1: 15/1 = 15.0000
Row 2: (15+20)/2 = 17.0000
Row 3: (15+20+10)/3 = 15.0000

Question 6 you can use python or other language
In the challenge, write a program to analyze a log file and summarize the results. Given a text file of an http requests log, list the number of requests from each host. Output should be directed to a file as described in program description below.
The format of the log file, a text file with .txt extension, follows. Each line contains a single log record with the following column (in order):
1. The hostname of the host making the request.
2. This column's value is missing and were replace by a hyphen.
3. This column's value is missing and were replace by a hyphen.
4. A timestamp enclosed in square brackets following the format [DD/mmm/YYYY:HH:MM:SS -0400], where dd is the day of the month, mmm is the name of the name of the month, YYYY is the year, HH:MM:SS is the time in 24-hour format, and -o4000 is the time zone.
5. The request, enclosed in quotes (e.g. "GET /images/NASA-logosmall.gif[ HTTP/1.0").
6. The HTTP response code
7. The total number of bytes sent in the response
Given the following log record:

Unicomp6.unicomp.net - - [01/jul/1995:00:00:06 -4000] "GET/shuttle/countdown/ HTTP/1.0" 200 3985
We can label each column in the record like this

Hostname - - Timestamp Request HTTP Response Bytes sent
Unicomp6.unicomp.net - - [01/jul/1995:00:00:06 -0400] "GET/shuttle/countdown/ HTTP/1.0" 200 3985

Function description
Your function must create a unique list of hostnames with their number of requests output to a file named records_filename where filename is replaced with the input filename. Each hostname should be followed by a space, the number of requests, and a newline. Order doesn't matter.
Constraints
• The log file has a maximum of 2 x 10^5 times records.
Input format
There is one line of input which contains the string filename read from STDIN.
Sample input 0
Hosts_access_log_00.txt
Sample Output 0
Given filename = "hosts_access_log_00.txt" process the records in hosts_access_log_00.txt and create an output file name records_hosts_access_log_00.yxt which contains the following rows:
Burger.letters.com 3
D104.aa.net 3
Unicomp6.unicomp.net 4.

Explanation 0
Unicomp6.unicomp.net - - [01/jul/1995:00:00:06 -0400]"GET/shuttle/countdown/ HTTP/1.0" 200 3985
Burger.letters.com - - [01/jul/1995:00:00:06 -0400] "GET/shuttle/countdown/liftoff.html HTTP/1.0" 304 0
Burger.letters.com - - [01/jul/1995:00:00:12 -0400] "GET/images/NASA-logosmaill.gif HTTP/1.0" 304 0
Burger.letters.com - - [01/jul/1995:00:00:12 -0400] "GET/shuttle/countdown/video/livevideo.gif HTTP/1.0" 200 0
D104.aa.net - - [01/jul/1995:00:00:13 -0400] "GET/shuttle/countdown/ HTTP/1.0" 200 3985
Unicomp6.unicomp.net - - [01/jul/1995:00:00:14 -0400] "GET/shuttle/countdown/count.gif HTTP/1.0" 200 40310
Unicomp6.unicomp.net - - [01/jul/1995:00:00:14 -0400] "GET/images/NASA-logosmaill.gif HTTP/1.0" 200 786
Unicomp6.unicomp.net - - [01/jul/1995:00:00:14 -0400] "GET/images/KSC-logosmall.gif HTTP/1.0" 200 1204
D104.aa.net - - [01/jul/1995:00:00:15 -0400] "GET/shuttle/countdown/count.gif HTTP/1.0" 200 40310

D104.aa.net - - [01/jul/1995:00:00:15 -0400] "GET/images/NASA-logosmaill.gif HTTP/1.0" 200 786

When the data is consolidated, it confirms the following:
• The host Unicomp6.unicomp.net made 4 requests
• The host Burger.letters.com made 3 requests
• The host D104.aa.net made 3 requests