C++程序调试、代做data编程、代写c/c++编程

日期：2021-05-20 10:37

C++ Implementation of Hash table with linear probing (worth

10%, due May 23rd 23:59PM, late submissions not accepted)

Mingyu Guo

1 Task Description

You are asked to use C++ to implement

? Hash table with linear probing

2 Submission Guideline

You must follow this guideline! Your submission will be marked automatically. Failure to

follow this guideline will result in 0.

Your submission should contain exactly one file: main.cpp.

You do not need to submit a design.

You are asked to implement a very specific hash table. The keys are lower-case English words (e.g., apple,

pear). The length of a key is at most 10. The hash function is “simply using the last character”. That is,

the hash value of apple should be e, and the hash value of pear should be r. Your hash table contains exactly

26 slots (hash value a to hash value z). The total number of English words/keys you need to deal with is at

most 26, so the table is never too small.

A table slot has three different statuses: “never used”, “tombstone”, and “occupied”. Table starts with

26 “never used” slots.

Searching works as follows: given a key, take its last character as the hash value. First try the corresponding

table slot, if the objective key is there, then you have found it. If the corresponding slot is never

used, terminate because we are certain that the objective is not in the table. If the slot is occupied but it’s

not the objective, or the slot is a “tombstone”, then we move on to the next slot (may need to wrap around

the table if the current slot is the last one). We keep trying until we either find the key or are certain that

the key does not exist in the table.

Insertion works as follows: First perform searching to ensure that the key does not exist. If it already

exists, then do nothing. If it does not, take the last character of a key as the hash value. If the corresponding

table slot is not occupied (either “never used” or “tombstone”), put the key there (the slot is now occupied).

If the corresponding slot is already occupied, try the next slot. Repeat trying until you find an unoccupied

slot.

Deletion works as follows: given a key, use the searching process to locate its slot. (If the key is not in

the table, then do nothing.) Once you find the key, change the slot status to “tombstone”.

You should start your program by initializing an empty hash table. Your program takes one line as

input. The input line contains n “modification moves” separated by spaces (1 ≤ n ≤ 26). The available

modification moves are

? AWord (Character A followed by a lower-case English word of length at most 10): Aapple means insert

key apple into the hash table. If apple is already in the table, do nothing.

? DWord (Character D followed by a lower-case English word of length at most 10): Dapple means delete

key apple from the hash table. If apple is not in the tree, do nothing.

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At the end, you need to go through the slots from a to z, and output all the keys separated by space.

You don’t need to worry about invalid inputs.

Sample input 1: Aaaa Accc Abbb

Sample output 1: aaa bbb ccc

Sample input 2: Abba Aaaa Acca

Sample output 2: bba aaa cca

Sample input 3: Abba Aaaa Acca Daaa

Sample output 3: bba cca

3 Marking

Marking will be done automatically. The total mark is 10 (1 for compiling and 9 for 9 test cases).

4 SVN Instructions

First of all, you need to create a directory under version control:

svn mkdir --parents -m "Creating ADSA Assignment 3 folder" https://version-control.adelaide.edu.au/svn/aXXXXXXX/2021/s1/adsa/assignment3/

aXXXXXXX should be your student ID. The directory path needs to be exactly “2021/s1/adsa/assignmentK”,

where “K” is the assignment number. To check out a working copy, type

svn checkout https://version-control.adelaide.edu.au/svn/aXXXXXXX/2021/s1/adsa/assignment3/ adsa-21-s1-assignment3/

cd adsa-21-s1-assignment3

svn add main.cpp

Commit the files to SVN:

svn commit -m "Adding ADSA assignment 3 main.cpp"

SVN helps keeping track of file changes (over different commits). You should commit your work early and

often.

5 Websubmission

You are asked to submit via the web interface https://cs.adelaide.edu.au/services/websubmission/.

The submission steps should be self-explanatory. Simply choose the correct semester, course, and assignment.

The websubmission system will automatically fetch the latest version of your work from your SVN repository

(you may also choose to submit older versions). Once your work is submitted, the system will launch a

script checking the format of your submission. Click “View Feedback” to view the results. Your mark will

be calculated offline after the deadline. You are welcome to resubmit for as many times as you wish (before

the deadline).

We will compile your code using g++ -o main.out -std=c++11 -O2 -Wall main.cpp. It is your responsibility

to ensure that your code compiles on the university system.

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1g++ has too many versions, so being able to compile on your laptop does not guarantee that it compiles on the university

system. You are encouraged to debug your code on a lab computer (or use SSH).

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