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]

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::string, 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

 

[David Harmon]

On 8 Feb 2007 08:25:40 -0800 in comp.lang.c++, "(e-mail address removed)"

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 8 Feb 2007 08:25:40 -0800 in comp.lang.c++, "(e-mail address removed)"

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 8 Feb 2007 08:25:40 -0800 in comp.lang.c++, "(e-mail address removed)"

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::string, int> called 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.]

On 8 Feb 2007 08:25:40 -0800 in comp.lang.c++, "(e-mail address removed)"

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, int> freq;
++freq["hello"];
assert( freq["hello"] == 1 );
}

 

[Default User]

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.com/c++-faq-lite/how-to-post.html>

 

[Jake]

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.com/c++-faq-lite/how-to-post.html>

*plonk*