Problem inputting numbers into vector from file

This is a discussion on Problem inputting numbers into vector from file within the C++ Programming forums, part of the General Programming Boards category; Hello! so, I'm implementing quicksort and selection sort using vectors. I have the following code. To run I use redirection. ...

  1. #1
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    Question Problem inputting numbers into vector from file

    Hello! so, I'm implementing quicksort and selection sort using vectors.
    I have the following code. To run I use redirection. i.e. ./program.out <datafile

    Code:
    int main()
    {
      int number;
      vector<int> list;
      cout << "QuickSort..." << endl;
      while (cin >> number)
        {
          list.push_back(number);
        }
      int left = 0;
      int size = list.size();
      int right = size-1;
      print(list); // testing sort
      quickSort(list, left, right);
      print(list); // testing sort
      cout << "Done" << endl;
    
      return 0;
    }
    But my vector seems to be empty?
    I've changed the while loop to
    Code:
    cin >> number;
    while (!cin.eof())
    {
      list.push_back(number);
      cin >> number;
    }
    That gives me a bad_alloc error though.

    Any tips? My sorts work with small sets, but I haven't been able to test larger 2000 and above sets yet because of this. :(

  2. #2
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    I'll reply to myself. I ALSO tried:

    Code:
     
    do {
        cin >> number;
        list.push_back(number);
      } while (number);
    and I STILL get CPU time limit exceeded :'(

  3. #3
    Registered User whiteflags's Avatar
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    Would you please post your data file?

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    The data file contains a series of random numbers using a different program that writes to a data.txt file.
    I use srand(time(0)); cout << rand();

    So the file looks like this:

    1485738376
    1444384990
    1816004519
    1128556181
    1946001519
    671306856
    902458063
    1329651005
    371347021
    2063196661
    1678323328
    1176164953

    times a lot. Im trying to time quicksort by having it sort these files of 2000, 4000, 6000, etc elements.

  5. #5
    Registered User whiteflags's Avatar
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    I can't really reproduce your problem on my end. If the file name is somehow not named correctly (such as a missing extension) the redirection of cin will not be effective, though.

  6. #6
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    Well what would be causing me to get a bad_alloc error? And/or CPU time limit exceeded?

    I add print statements after everything and the error seems to be only with adding ints to the vector with the while loop.
    If i print out the capacity and size, it says zero for both, even after the push_back stuff.

    I don't understand

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