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Please read the following instructions carefully before submitting assignment.

It should be clear that your assignment will not get any credit if:


  • The assignment is submitted after due date.
  • The submitted assignment does not open or file is corrupt.
  • Assignment is copied(partial or full) from any source (websites, forums, students, etc)





The objective of this assignment is:

  • Learn to code, edit, compile and execute C++ program.
  • Learn to manipulate and navigate through text files.
  • Learn to create and use user defined functions.
  • Learn to use string manipulation functions.



  • Code should properly be indented and well commented.
  • Follow C/C++ naming conventions while using variables, functions etc.
  • Use only Dev-C++ for this assignment. If you are using any other tool then mention it at top of your code file as comments.


Assignment Description


In this assignment, you are required to write c++ code that will protect the provided text file using the protection mechanism given in guidelines. It will also check the security of file and if any change is made in the contents of protected file, it will point out the file as changed.


Protection mechanism:

The program will protect the file by generating a protection key on the basis of contents of the file. The key will be saved at the end of the file with “%” symbol as prefix. This key will be used to detect either the file contents are changed or not e.g. if file contents are changed the new key generated will not match the existing one, leading to conclusion that file contents have been changed.


Solution guidelines

The program should operate in following sequence.

  • Program will prompt the user to enter the file name in current directory.
  • System will show a menu with two options:
    • Protect the file
    • Check security status
  • In case user selects the first option (i.e. protect the file), the system will perform the following steps:
    • Read the file
    • Check if the file is already protected or not.
    • In case if file is not protected, program will protect it by the protection mechanism defined above.
    • If file is already protected, system will display appropriate message and exit.
  • If user selects the second option (i.e. check security status), the system will perform following steps:
    • Read the entire file and if key does not exist (i.e. file is not already protected), program will display the message to protect the file first and display menu.
    • If file is already protected, the system will read the contents along with the already existing key. On the basis of contents read, a new key will be generated. If this new key and the existing one (read from the file) do not match, it means that the contents of protected file are changed and vice versa.


Important note

A text file (data.txt) is attached with assignment, use it for protection checking. Video file (Output-Demo.mp4) of desired function is also attached with assignment. Watch the demo video carefully to understand the required functionality (output) of program. Your program should work as per functionality performing in demo video file. You do not need to send text file with your solution. Just upload .cpp file from your LMS account. For any query related to assignment no. 3 contact us at


You are required to submit your solution C++ program through LMS i.e. .cpp file. 

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Replies to This Discussion

Cs201 Assignment No 3 


access  denied on this server plz upload through dropbox or anyother hosting\

Need some help on 3rd assignment

Please Discuss here about this assignment.Thanks

Our main purpose here discussion not just Solution

We are here with you hands in hands to facilitate your learning and do not appreciate the idea of copying or replicating solutions.

plz help about assignment

i don't understand 

I've solved the problem , 

If anyone needs help in algorithm or understanding what exactly teacher asked to work I can help , but remember I wont give source code like other will only help you and teach you about the problem , so only ask from me if you have passion to learn programming


plase tell me kon sy leactures ko main smj k dykh to mujy is assigment ko solve krny main asani ho gi?

Asalalm o alikum 

please help me out to solve this assignment ...i will not ask for code but tell me the the algorithm ....

ok here are the things you have to do , 

to protect the file create a mechanism that will generate a unique key based on the written data , like , the data in the file is "I am a programmer" then the key will be 49

and if the data is "I am a software engineer" the key will be 80 , you have to think a way how to do that

then write that key in the end of the file using app mode

and in checking the simple thing you have to do is read the key and check via the mechanism you have generated the key that data is still the same or not and then display the msg accordingly on console :)

thank you .... if i want to use a function so how would i pass the address of the file as an  argument.... 

lecture 18 and 19  and a lil bit of thinking :p


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