Counting frequency of words in a text file using STL containers

[writeanand]

How can I count the frequency of words in a ASCII File using STL?
a) I dont know what words will be found in the file
b) The max number of occurrences is 10,000 per word (in case that
matters)

Can anyone give me an example program and compare/contrast the use of
various STL containers for this problem?

[Thomas Tutone]

On Feb 8, 11:14 am, "writean...@gma il.com" <ekr...@gmail.c omwrote:

How can I count the frequency of words in a ASCII File using STL?
a) I dont know what words will be found in the file
b) The max number of occurrences is 10,000 per word (in case that
matters)

Use a std::map<std::s tring, int>. Look up std::map in your
coursebook, and it should be fairly obvious how to do this. If you
have trouble, post some code and explain the problem you're having.

Best regards,

Tom

[writeanand]

Tom,

THank you. When the word already exists in the map, then I can use freq
++ in the "int" part of the map.
My problem is, when I find a new word, there is no existing entry, so
I cant use (freq++) in the "int" part of the map.
Can u give an example for the above?

Thanks
On Feb 8, 9:18 am, "Thomas Tutone" <Thomas8675...@ yahoo.comwrote:

On Feb 8, 11:14 am, "writean...@gma il.com" <ekr...@gmail.c omwrote:

How can I count the frequency of words in a ASCII File using STL?
a) I dont know what words will be found in the file
b) The max number of occurrences is 10,000 per word (in case that
matters)

Use a std::map<std::s tring, int>. Look up std::map in your
coursebook, and it should be fairly obvious how to do this. If you
have trouble, post some code and explain the problem you're having.

Best regards,

Tom

[David Harmon]

On 8 Feb 2007 08:25:40 -0800 in comp.lang.c++, "wr********@gma il.com"
<ek****@gmail.c omwrote,

>THank you. When the word already exists in the map, then I can use freq
++ in the "int" part of the map.
My problem is, when I find a new word, there is no existing entry, so
I cant use (freq++) in the "int" part of the map.

Why not? Just use operator[] and let it create a new entry.

[writeanand]

On Feb 8, 10:05 am, David Harmon <sou...@netcom. comwrote:

On 8 Feb 2007 08:25:40 -0800 in comp.lang.c++, "writean...@gma il.com"
<ekr...@gmail.c omwrote,

THank you. When the word already exists in the map, then I can use freq
++ in the "int" part of the map.
My problem is, when I find a new word, there is no existing entry, so
I cant use (freq++) in the "int" part of the map.

Why not? Just use operator[] and let it create a new entry.

How Though? Sorry for my ignorance, I need a simple example since I am
new to this :(

[Thomas Tutone]

On Feb 8, 12:10 pm, "writean...@gma il.com" <ekr...@gmail.c omwrote:

On Feb 8, 10:05 am, David Harmon <sou...@netcom. comwrote:

On 8 Feb 2007 08:25:40 -0800 in comp.lang.c++, "writean...@gma il.com"
<ekr...@gmail.c omwrote,

>THank you. When the word already exists in the map, then I can use freq
>++ in the "int" part of the map.
>My problem is, when I find a new word, there is no existing entry, so
>I cant use (freq++) in the "int" part of the map.

Why not? Just use operator[] and let it create a new entry.

How Though? Sorry for my ignorance, I need a simple example since I am
new to this :(

Suppose you have a std::map<std::s tring, intcalled wordCount.
Suppose the next word you have is stored in a std::string called
word. Suppose that word is currently equal to "the". Now, you want
to increment its count accordingly. Then just do this:

++wordCount[word];

This will work whether word's value previously existed in wordCount or
not.

If you have more problems, post them.

Best regards,

Tom

[Daniel T.]

In article <11************ **********@a75g 2000cwd.googleg roups.com>,
"wr********@gma il.com" <ek****@gmail.c omwrote:

On Feb 8, 10:05 am, David Harmon <sou...@netcom. comwrote:

On 8 Feb 2007 08:25:40 -0800 in comp.lang.c++, "writean...@gma il.com"
<ekr...@gmail.c omwrote,

>THank you. When the word already exists in the map, then I can use freq
>++ in the "int" part of the map.
>My problem is, when I find a new word, there is no existing entry, so
>I cant use (freq++) in the "int" part of the map.

Why not? Just use operator[] and let it create a new entry.

How Though? Sorry for my ignorance, I need a simple example since I am
new to this :(

int main() {
map<string, intfreq;
++freq["hello"];
assert( freq["hello"] == 1 );
}

[Default User]

wr********@gmai l.com wrote:

Tom,

Please don't top-post. Your replies belong following or interspersed
with properly trimmed quotes. See the majority of other posts in the
newsgroup, or the group FAQ list:
<http://www.parashift.c om/c++-faq-lite/how-to-post.html>

[Jake]

On Feb 8, 3:01 pm, "Default User" <defaultuse...@ yahoo.comwrote:

writean...@gmai l.com wrote:

Tom,

Please don't top-post. Your replies belong following or interspersed
with properly trimmed quotes. See the majority of other posts in the
newsgroup, or the group FAQ list:
<http://www.parashift.c om/c++-faq-lite/how-to-post.html>

*plonk*