Thread: Time to test your C++ abilities...

Originally posted by Darkman
There's no ansi way of doing it?

string and getline are in the standard namespace for a reason.

gg

Originally posted by Zach L.
To math patterns in the string, though, you'll have to use some complex coding, or something like a regular expression library. I believe Boost has one of those ( www.boost.org ).

Thought that was part of your signature for some reason...

thats if you are going to go to a merchant, and are going to talk to them, i prefer either a list of what he has, or a user interface with a the items and words.

Code:

user: /buy
merchant: i have:
1) a rusty short sword - 1 silver
2) a jaged short sword - 5 silver
3) an iron short sword - 2 gold
4) a steal short sword - 4 gold
5) a fine alloy short sword - 5 platinum
user: /buy 3
merchant: you dont have 2 gold.
user /buy 2
merchant: thank you for your buisness
you have 5 less silver
you have 6 silver less

but thats only for a text based game, UI's are better imo.

but a programer does, and can put "purchase", "buy", and even a few miss spellings for "purchase"

Yes

What you know about a phrase is that each word is seperated by a space.

So you take this fact and use it too your advantage.
you could use a vector or an array or another contairer to hold it. i gona use an array but i'd suggest using a vector as it solves the problem of dynmic memory allocation for you, but you could use an array and do some dynamic stuff.

Code:

...
string userIn;
char wordArray[6][5]; // i know my inpputed phrase has 6 words and longest word is 5 letters
int x, y, z;
x= 0; y = 0; z = 1;

// user says this "I want to buy a sword."
cin >> userIn;
char currentLetter = userIn[0];
while (currentLetter) {
 if (currentLetter != "." && currentLetter !=" ") {
  wordArray[x][y] = currentLetter;
  y++;
 }
if (currentLetter == " ") { // your moving onto another word.
  x++;
  y = 0;
  }
currentLetter  = userIn[z];
z++;
}

Alright so that would break it up into individual words, After that you jsut have to check it for what you need.

NOte this is untested code and is realy ment jsu tto give you an idea of how you might be able to solve your problem.

Search the web for "natural language parsers." Many MUDs have very complex input parsers nowadays that let you do things like:

> get the first green sword in the 2nd wood crate
> sell it to bob

Everquest's system is actually very, very simple. It could be easily copied with simple code like the following:

Code:

#include <iostream>
#include <string>
#include <map>


class Responder
{
public:
  std::string sayto(std::string msg)
  {
    std::map<std::string, std::string>::iterator itr = responses.begin();
    for( ; itr != responses.end(); ++itr)
    {
      if(msg.find(itr->first) != std::string::npos)
        return itr->second;
    }

    return "I do not understand.";
  }

  void add_response(std::string key, std::string resp)
  {
    responses[key] = resp;
  }

private:
  std::map<std::string, std::string> responses;
};

int main()
{
  Responder r;

  r.add_response("hail", "Hello traveller! Hrm, now where did I put those [rusty swords]?");
  r.add_response("rusty sword", "Bring me rusty swords and I'll give you a [prize]!");
  r.add_response("prize", "Shh! I can't tell you abou that!");

  std::cout << "Type 'hail' to start and 'quit' to quit." << std::endl;

  std::string s;

  do
  {
    std::cout << "Say what? " << std::flush;
    std::getline(std::cin, s);

    if(s != "quit")
    {
      std::string response = r.sayto(s);
      std::cout << "Bob says, '" << response << "'" << std::endl;
    }

  } while(s != "quit");

  return 0;
}

And a sample run:

$ ./a.out
Type 'hail' to start and 'quit' to quit.
Say what? hail
Bob says, 'Hello traveller! Hrm, now where did I put those [rusty swords]?'
Say what? What rusty swords are you talking about?
Bob says, 'Bring me rusty swords and I'll give you a [prize]!'
Say what? Wow?! What type of prize?
Bob says, 'Shh! I can't tell you abou that!'
Say what? quit
$


Hope that helps.

-tf