COM1001 Lab 3 -Solved

Write a  Python program   which   takes a   sequence of   inputs   that  contain multiple     source  strings  and    multiple   query    strings; prints    the         occurrences  of query    strings  within  the source  strings. The  output  format is  speci<ied   below.  Please   also look   at    the  sample I/O   <iles.                     

Speci&ication details:               

-    Source   and query  strings  will  be    provided  in  two     different The number  of  strings  are  not         <ixed,    i.e.  can  change in    different  runs.            

-    You    can   assume that  there  will   be  at  least  on source  strinand        one   query  string.   

-    If    there    are   no   occurrences   of   the query  strings  within  any  source  string,   you   will   print  None.   

-    You    will   be  printing the occurrences    in   the  order    that        checks  for each source  sting,     all the   query    strings. (Check your      results  withthe   sample outputs    for   compatibility    of            the         order)  

Constraints: 

-    You are not allowed to use any string class func1ons, such as str.find() or similar. You are expected to implement your own algorithm by itera1ng over the string content as in the previous lab assignment. 

-    You are not allowed to import any modules that helps iden1fica1on of substrings as well. We will go over the source files one by one and if we iden1fy any external library func1ons in your source codes, we will treat your submission as chea1ng and you will get 0.  

Hints: 

This 1me, since we have recently learned lists, you will read the strings given in a line using:

               inputs = input().split() 

ACer reading, inputs variable is bound to a list of strings. You can iterate over the individual items using in operator in a for loop, i.e. for item in inputs:.  

You are expected to implement your own solu1ons to determine every occurrences of each query strings within the source strings. As we have seen, you can iterate over individual characters of a string, str, using in operator; e.g. for chr in str:. Alterna1vely, you can use len() func1on and range() func1on in itera1ons within strings. 

Since there will be mul1ple nested loops, it would be a good prac1ce to define a func1on that iden1fies the substring rela1on and other necessary informa1on, given two strings. You will be able to construct your solu1on easier and cleaner that way. It will also help you to iden1fy possible sources of errors easily during development. Otherwise, you may have difficulty in 1me management.  

I personally suggest that, first write this func1on and test it providing different string pairs. ACer making sure that your substring iden1fica1on func1on works without problems, you can very efficiently implement the parts that integrates input reading and output formaNng etc., in quite a short amount of 1me. In every new step, such as reading the inputs part, check if everything is fine by monitoring the content that you read (like prin1ng temporarily or debugging etc.).  

I/O Format: 

Input format:  

[[string][Space]]+ [Newline] [[string][Space]]+

Output format:  

Repeat for each occurrence i: 

<source_string_i>[space]<query_string_i>[space]<total_number_of_occurrences_in_source_i>[space

]<start_indexes_list>[Newline] if no occurrences are found: None 

Note that: 

1-  Sample input and output files are provided.  

2-  [x]+ means, one or more elements of x

TesWng: 

You are provided with some sample I/O files. Assume that input.txt stands for a sample input and output.txt stands for the corresponding output file and your source code is named as Lab3.py; you can test your program from the command line using the following commands. (>: stands for command prompt)  

> python Lab3.py < input.txt > my_output.txt

This command redirects the inputs in the input.txt file as if they are provided from the command line to your python code. The outputs, which you generate using the print() func1on in your source codes, are redirected to my_output.txt file.

You can then check if my_output.txt file is exactly the same with the provided output.txt file, using diff command from the command prompt:

> diff output.txt my_output.txt