anagrams

This is a discussion on anagrams within the C Programming forums, part of the General Programming Boards category; how would i go about coding an algorithm that takes a word and gives its anagram? need some help figuring ...

  1. #1
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    anagrams

    how would i go about coding an algorithm that takes a word and gives its anagram? need some help figuring out the steps i need to take. An anagram is a word created by another word by changing the order of the letters. ex. use -> sue. so this would be equal to 3!, so i would get 6 different words correct?

    what i was thinking of doing is make a copy of the original word - 1st letter and place that letter at the end of the word, but then at some point i will get the same word again . then take the 2nd letter and place it at the end, then take the 3rd letter and place it at the end again.

    or would it be better and more efficient if i ignore the letter all together and focus on arranging the indeces that hold the letters? any suggestions?
    When no one helps you out. Call google();

  2. #2
    ATH0 quzah's Avatar
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    You might do a board search for 'permeation'. If you're ever stuck on how to do something in code, try to think of it as how you yourself would do the job. Then break that down into the smallest steps you can think of gradually, and there you'll end up with your pseudocode.

    You can do this task with some loops. Loop through the word starting with the first letter, and switch around the rest of them one at a time. Or you can use recursion, which may be easier.

    Quzah.
    Hope is the first step on the road to disappointment.

  3. #3
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    you are right this is done using permutation and i know how permutation works but i dont need the actual number of permutation but each word individual, that means i will have to break out of the loop after each permutation, right?
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  4. #4
    ATH0 quzah's Avatar
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    Or just when you hit the end of a string. If you're just moving one character at a time down the line, simply stop when you hit the end.

    Quzah.
    Hope is the first step on the road to disappointment.

  5. #5
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    nested for loops might be of help to you. keeping first one constant, change the others, here you can use recursions to change the order of the letters. if you use recursions and a loop, i think it will serve your purpose.
    - PING !
    Code:
    >+++++++++[<++++++++>-]<.>+++++++[<++++>-]<+.+++++++..+++.[-]>++++++++[<++++>-] <.>+++++++++++[<++++++++>-]<-.--------.+++.------.--------.[-]>++++++++[<++++>- ]<+.[-]++++++++++.

  6. #6
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    wouldnt this create double words?
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  7. #7
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    Quote Originally Posted by InvariantLoop
    how would i go about coding an algorithm that takes a word and gives its anagram? need some help figuring out the steps i need to take.
    The algorithm is available to you if you take a look at the implementation of the STL next_permutation function (in the <algorithm> header). Your task would then be to code a C version of it that works on character arrays... which looks to be fairly simple. Note: this algorithm depends on the initial input string being in sorted order for it to work properly, i.e. you would start by giving it an initial string of "esu" using your example.

    Quote Originally Posted by InvariantLoop
    An anagram is a word created by another word by changing the order of the letters. ex. use -> sue. so this would be equal to 3!, so i would get 6 different words correct?
    You have 6 different permutations yes, but whether or not those permutations equate to actual words is another matter.
    "Owners of dogs will have noticed that, if you provide them with food and water and shelter and affection, they will think you are god. Whereas owners of cats are compelled to realize that, if you provide them with food and water and shelter and affection, they draw the conclusion that they are gods."
    -Christopher Hitchens

  8. #8
    ATH0 quzah's Avatar
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    Code:
    #include <stdio.h>
    int main( void )
    {
            char word[] = "abcdefg";
            int x,z;
            for( x = 1; word[x]; x++ )
            {
                    z = word[x];
                    word[x] = word[x-1];
                    word[x-1] = z;
                    printf("%s\n", word );
            }
            return 0;
    
    }
    Here's one run through. I'll leave the rest to you.

    Quzah.
    Hope is the first step on the road to disappointment.

  9. #9
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    yes thats right, the fact that some of the words created have no meaning is not an issue.
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  10. #10
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    I bet you could come up with a few rules that would help look for words without a dictionary. Perhaps rules like "no more than two vowels in a row", "no more than four consonants in a row", or "no more than two of the same letter in a row i.e. no WWW". Of course, implementing that might be a hassle.

    edit: Of course, if it's not an issue, then I wouldn't bother with it.
    If I did your homework for you, then you might pass your class without learning how to write a program like this. Then you might graduate and get your degree without learning how to write a program like this. You might become a professional programmer without knowing how to write a program like this. Someday you might work on a project with me without knowing how to write a program like this. Then I would have to do you serious bodily harm. - Jack Klein

  11. #11
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    ah. I need to read hour 12, working with arrays before i actually start doing anything like this. Theres too much i dont understand yet.
    When no one helps you out. Call google();

  12. #12
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    lol,

    Unfortunately, using a permutation algo to solve anagrams is impratical - as you may have realised. A word of nine letters would be 9! and this takes up too much processor time. The solution is simple - implement a letter frequency counter and then check it with a dictionary file.


    Code:
    #include <stdio.h>
    #include<iostream.h>
    #include<string.h>
    #include<fstream.h>
    
    int main()
    {
    
     fstream file_pointer_in;
     fstream file_pointer_out;
     
     file_pointer_in.open("dict.txt",ios::in);
     file_pointer_out.open("contain.txt",ios::out);
    
     int a,b;
     char array[81];
     cout<<"Enter word:"<<endl;
     cin>>array;
     cout<<"Calculating possibilities..."<<endl;
     cout<<" "<<endl;
     cout<<" "<<endl;
     int mass;
     mass = strlen(array);
     
    
     
    
    
     
    
      char alphabet[28]={"/abcdefghijklmnopqrstuvwxyz"};
      int alphacount[26];
      int betacount[26];
     
    
      //initialise
       for (int i=1; i<27; i++)
        {
         alphacount[i]=0;
        }
    
        for(a=0; a<mass; a++)
        {
         
          for(int j=1; j<27; j++)
            {
             if (array[a]==alphabet[j])
              {
              alphacount[j]++;
              }
             }
            }
    
    
     //open dictionary file and read>>
     char x[81];
    
     do{
        file_pointer_in>>x;
        int size;
    
    
        size = strlen(x);
    
        for (int i=1; i<27; i++)
        {
         betacount[i]=0;
        }
    
    
    
    
    
    
        for (int i=0; i<size; i++)
        {
         for (int j=1; j<27; j++)
          {
           if (x[i]==alphabet[j])
            {
             betacount[j]++;
            }
           }
          }
           int counter=0;
           int hello=0;
          for (int k=1; k<27; k++)
          {
           if (betacount[k]==alphacount[k])
            {
            hello++;
            }
    
    
          if (betacount[k]<=alphacount[k])
          {
           counter++;
          }
    
          }
            if (hello==26)
           {
           file_pointer_out<<"** BINGO ***:"<<x<<endl;
           }
           if (counter==26)
           {
           file_pointer_out<<x<<endl;
           }
    
    
          
    Simple yet elegant
              
    
    
    
         
    
    
        }while(file_pointer_in.peek()!=EOF);
        cout<<"END-";
        int stop;
        cin>>stop;
    
        file_pointer_in.close();
        file_pointer_out.close();
    
    
    }

  13. #13
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    This is the C board...C++ and C make look a lot alike, but they're not the same thing.
    If you understand what you're doing, you're not learning anything.

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