Okay but what other underlying container I can give?

For priority queue it can either be a vector or a deque. For stack it can be vector, deque or list. For queue it can be list or deque

It's because that vector and deque both allow random access??

If I learn programming is there need to learn web design?

No need to, especially if we're speaking about C/C++

No. You create a view that masks the data. Whenever you are asked to retireve data from a table, you fetch data from that view instead. So here the DB masks the data. The data stored in the DB is in clear text form, but the ones fetched through the view will be in masked form. I have already suggested 3 options for you. Read about them and see which one is applicable for yout use case

string query2= "update test set name = concat (substr(name, 1,3), repeat ('',char_length(name)-3))";

So for I could write this only🥺

Q4. Write a program that reads from the user a matrix Nx3. The matrix contains employees' information. The first column holds employees' names. The second column contains vaccine status, which is either 0 or 1. Ones for employees who got the vaccine and zeros for not taking it. The 3rd column for COVID infected employees, which is either "yes" or "No". Yes, is for currently infected employees and No is for not infected. 1. Find the percentage of employees who got the vaccine. 2. Find the percentage of employees currently infected with COVID.

What's your question? What have you done so far? Where did you get stuck?

Writing Cplus

string query2= "update test set name = concat (substr(name, 1,3), repeat ('',char_length(name)-3))";

If you update the table,you can't unmask it. Btw your questions are no longer C++ questions.

If you update the table,you can't unmask it. Btw your questions are no longer C++ questions.

May be I shoul write an encode func in c++ func and call it in SQL stmt

You can just retrieve the data from the database as is using a simple select statement and mask PII before displaying it.

Sorry I must have understood the question wrong.. this is the exact question.. Write a C++ or Java Program to mask the data use any of your interested perturbation techniques Note: the codehas to to connect to database and fill the entries with masked values.

This is nice but in the question he said update the tables

If you update the tables with a masked value (like how you are doing), you can't unmask it. Is unmasking required? If yes, then your only option then is to encrypt the PII in each record with an encryption key and store the encryption key in some other table (not a secure way of doing things)

Unmasking is required I guess other wise data will be lost

Guys, quick question: How to create a class with an array member, whose size is given by the class constructor, such as the following (ugly) code: class A { public: A(int size) { nums = std::malloc(size); } private: int nums[]; };

Is there anyone who knows about FUNCTIONAL PROGRAMMING , CLEAN.

Since sizeof is a compile time operator, can we say that the result produced by it is hardcoded into the executable binary?

Yes.

Ask your question directly as long as it is related to functional programming support in C++ (which is very limited btw). If you intend to use Haskell, Erlang or other languages or if your doubt is on Lambda Calculus, go to a group appropriate for that.

soda contains 1/10th of 1% artificial sweetener. Use a variable declaration with the modifier const to give a name to this fraction. You may want to express the percent as the double value 0.001. Your program should allow the calculation to be repeated as often as the user wishes.

Ask your question directly as long as it is related to functional programming support in C++ (which is very limited btw). If you intend to use Haskell, Erlang or other languages or if your doubt is on Lambda Calculus, go to a group appropriate for that.

#include <iostream> using namespace std; int main() { int T,N,S,f; cin>>T; for(int i=0;i<T;i++) { cin>>N>> S; f=abs(S-N); if(N==S){ cout<<N<<endl; } else if(S==1){ cout<<"1"<<endl; } else if(S==0){ cout<<"0"<<endl; } else{ cout<<f<<endl; } } // your code goes here return 0; }

Can you detect problem?

Yes.

int main(void) { cout << endl; cout << "Masked values are" << "\n"; DisplayMasked(); cout << "\n"; cout << "\n"; cout << "UnMasked values are" << "\n"; cout << "\n"; DisplayUnmasked(); cout << "\n"; cout << "\n"; compute_alphabeticallyfirst(); return EXIT_SUCCESS; try { sql::Driver* driver; sql::Connection* con; sql::Statement* stmt; sql::ResultSet* res; sql::PreparedStatement* prep_stmt; driver = get_driver_instance(); con = driver->connect("tcp://localhost", "root", "27640822aC@"); con->setSchema("wrestling"); stmt = con->createStatement(); res = stmt->executeQuery("SELECT * from personal_info1"); while (res->next()) { sql::ResultSet* res1; string name = res->getString(2); reverse(name.begin(), name.end()); name = "*" + name + "*"; string val = res->getString(2); stmt->executeUpdate("UPDATE personal_info1 SET Name = '"+ name+"' WHERE Name = '"+ val+"'"); stmt->execute("COMMIT"); } delete res; delete stmt; delete con; } catch (sql::SQLException& e) { cout << "# ER: SQL-Exeption in " << FILE; } cout << endl; return EXIT_SUCCESS; }

You are returning EXIT_SUCCESS before the try catch block. How will the try catch block execute? And you are just reversing the name and adding a * before and after and updating the table. How is that masking? And your SQL query for updating is inefficient. All tables created using the normalisation rules will have an index key. Use that index key as the search id in the WHERE clause of your SQL statement. It is inefficient to do a string search through a DB table.

How will I know index key

Just check the DDL for personal_info table. It will tell you what the primary index is.

Can anyone tell me the optimised approach to this problem. There's a public private key pair and you know the public key and also you know the following relationship is used to encrypt the message. Pub^prv = pub+prv Pub public key Prv private key ^ bitwise xor + Addition Now for a given public key I need to print the smallest private key possible And the constraints are both pub and prv are in range from 1 to 10e18 I did this question by doing this For a given pub key I iterated from 1 to pub and for every number I tried whether the condition holds true. If yes I return that number as my answer. But this approach will take O(n) time and it gave me a TLE.

Can anyone tell me the optimised approach to this problem. There's a public private key pair and you know the public key and also you know the following relationship is used to encrypt the message. Pub^prv = pub+prv Pub public key Prv private key ^ bitwise xor + Addition Now for a given public key I need to print the smallest private key possible And the constraints are both pub and prv are in range from 1 to 10e18 I did this question by doing this For a given pub key I iterated from 1 to pub and for every number I tried whether the condition holds true. If yes I return that number as my answer. But this approach will take O(n) time and it gave me a TLE.

BTW your approach is not O(n). It is exponential complexity

Why it's exponential

But it can't be 0

It is exponential because the input is not a number of items N but a single number N. Your algorithm's complexity is O(2^lg_2(N)) where lg_2(N) is the number of bits in your input.

Can anyone tell me the optimised approach to this problem. There's a public private key pair and you know the public key and also you know the following relationship is used to encrypt the message. Pub^prv = pub+prv Pub public key Prv private key ^ bitwise xor + Addition Now for a given public key I need to print the smallest private key possible And the constraints are both pub and prv are in range from 1 to 10e18 I did this question by doing this For a given pub key I iterated from 1 to pub and for every number I tried whether the condition holds true. If yes I return that number as my answer. But this approach will take O(n) time and it gave me a TLE.

I am still not able to understand it. I think like this, say I get the input as a number n (say it's 23) Now for 23 what I do is, I go from 1 to 23 and check is there any number existing which follows the condition. Thus for a number n I am doing n number of operations.

This is an algorithm question and not exactly a fit for this community. Here is a hint on how to solve it. Use the properties of xor. You want the top most bits of the private key to be 0 as far as possible. Adding a 1 bit to another 1 bit creates a carry over of 1 bit. xoring any bit with 0 gives you 1. So start from the least significant bit and try to find the position of the bit in public key where no carry over will be required and all bits beyond that bit in the private key will be 0. To find the position of the bit of interest, you will have to substitute 0 and 1 starting from LSB in the private key and check the xor and the addition cases. This would be O(lgN)

Guys a little question regarding C and unix system programming when I register a signal handler with signal (SIGINT, handler) in the main thread what happens when the signal is sent? is it propagated to other threads? affects all threads? is the handler run for each thread? thanks in advance to anyone who tries to clarify my ideas

The signal will be sent to any one thread that hasn't blocked the signal. The thread is chosen at random by the kernel.

So to a single thread

Yes

Thank you very much for the clarification

You can use pthread_sigmask to control which thread receives the signals but. This is mostly done to ensure that all signal handling happens in that specific thread I think Linux kernel delivers the signals by default to the main thread but BSD kernels will deliver them arbitrarily. So if you care about portability, you will use a signal mask to control how the signals are handled so that it works across distributions.

Yes thank you, currently I do not need to block the signal in the threads, I needed to print the contents of a shared buffer, but I did not understand if the signal was propagated to all threads or to only one.

It will be sent to only one thread

Now i have this: #include <iostream> #include <ctime> #include <unistd.h> using namespace std; string gen_random(int arg, char *argv[]) { std::string tmp_s; static const char alphanum[] = "0123456789" "ABCDEFGHIJKLMNOPQRSTUVWXYZ" "abcdefghijklmnopqrstuvwxyz"; srand( (unsigned) time(NULL) * getpid()); tmp_s.reserve(argv[1]); for (int i = 0; i < argv; ++i) tmp_s += alphanum[rand() % (sizeof(alphanum) - 1)]; return tmp_s; } int main(int argc, char *argv[]) { cont << argv[1] << endl; cout << gen_random() << endl; return 0; }

gen_random takes two parameters, but you are calling it without any. Does changing the call to gen_random in main to gen_random(argc, argv) fix your problem? I didn't understand your question but.