How to find Index positions with a vector STL?

This is a discussion on How to find Index positions with a vector STL? within the C++ Programming forums, part of the General Programming Boards category; Hello, vector <int>my_array my_array is 32 in size. The contents of my_array is: 11110000011111110000011111.111 I want to know the 4 ...

  1. #1
    Registered User
    Join Date
    Jan 2008
    Posts
    4

    How to find Index positions with a vector STL?

    Hello,

    vector <int>my_array

    my_array is 32 in size.

    The contents of my_array is:
    11110000011111110000011111.111


    I want to know the 4 index positions of '0'.


    How do I do it?


    Thanks,
    codeguy

  2. #2
    C++ Witch laserlight's Avatar
    Join Date
    Oct 2003
    Location
    Singapore
    Posts
    21,448
    I want to know the 4 index positions of '0'.
    What do you mean by the "4 index positions of '0'"?
    C + C++ Compiler: MinGW port of GCC
    Version Control System: Bazaar

    Look up a C++ Reference and learn How To Ask Questions The Smart Way

  3. #3
    Registered User
    Join Date
    Jan 2008
    Posts
    4
    I meant the four in color:

    11110000011111110000011111.111


    -codeguy

  4. #4
    and the Hat of Guessing tabstop's Avatar
    Join Date
    Nov 2007
    Posts
    14,185
    Iterate through the vector. When the number changes from 1 to 0 or from 0 to 1, make a note.

  5. #5
    The larch
    Join Date
    May 2006
    Posts
    3,573
    I guess you'll have to loop over the entire vector, keep a count of (consequtive?) 0-s and then decide whether a particular 0 is the one that you are interested in.
    I might be wrong.

    Thank you, anon. You sure know how to recognize different types of trees from quite a long way away.
    Quoted more than 1000 times (I hope).

  6. #6
    and the hat of sweating
    Join Date
    Aug 2007
    Location
    Toronto, ON
    Posts
    3,545
    There's also the std::find() function in the <algorithm> header, but then you'll have to convert the iterator it returns to an index (try the std::distance() function in <iterator>).

  7. #7
    Algorithm Dissector iMalc's Avatar
    Join Date
    Dec 2005
    Location
    New Zealand
    Posts
    6,295
    Quote Originally Posted by codeguy View Post
    I meant the four in color:

    11110000011111110000011111….111
    Er okay, cause there's no way we could have guessed that from the previous post!

    Do you mean that each integer in the vector holds a single 1 or 0, or do you mean to treat this as some kind of bitset where each int holds 32 1's or 0's?
    My homepage
    Advice: Take only as directed - If symptoms persist, please see your debugger

    Linus Torvalds: "But it clearly is the only right way. The fact that everybody else does it some other way only means that they are wrong"

Popular pages Recent additions subscribe to a feed

Similar Threads

  1. Function to check memory left from malloc and free?
    By Lechx in forum C Programming
    Replies: 4
    Last Post: 04-24-2006, 05:45 AM
  2. deleting a node by index
    By mouse163 in forum C++ Programming
    Replies: 4
    Last Post: 02-24-2005, 07:13 AM
  3. Getting the index of a list box to show in a msgbox
    By Mystical in forum C++ Programming
    Replies: 4
    Last Post: 10-02-2004, 03:17 PM
  4. file index update error
    By daluu in forum C Programming
    Replies: 1
    Last Post: 04-28-2003, 02:47 AM
  5. Variable question I can't find answer to
    By joelmon in forum C++ Programming
    Replies: 3
    Last Post: 02-12-2002, 03:11 AM

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21