Replacing words in a sentence? - c++

Question

I'm trying to replace multiple words with their "pirate pair", for example:
Normal: "Hello sir, where is the hotel?"
Pirate: "Ahoy matey, whar be th' fleagbag inn?"
This is what I tried before:
#include<iostream>
#include<string>
#include<conio.h>
using namespace std;
void speakPirate(string s);
int main()
{
string phrase;
cout << "Enter the phrase to Pirate-Ize: ";
getline(cin, phrase);
speakPirate(phrase);
_getch();
return 0;
}
void speakPirate(string s)
{
int found;
// list of pirate words
string pirate[12] = { "ahoy", "matey", "proud beauty", "foul blaggart", "scurvy dog", "whar", "be", "th'", "me", "yer", "galley", "fleabag inn" };
// list of normal words
string normal[12] = { "hello", "sir", "madam", "officer", "stranger", "where", "is", "the", "my", "your", "restaurant", "hotel" };
for (int i = 0; i < s.length(); i++)
{
found = s.find(normal[i]);
if (found > -1)
{
string left = s.substr(0, found - 1); // get left of the string
string right = s.substr(found + pirate[i].length(), s.length()); // get right of string
s = left + " " + pirate[i] + " " + right; // add pirate word in place of normal word
}
}
cout << s;
}
But it didn't really work and was very buggy, so I tried using the replace() function instead:
#include<iostream>
#include<string>
#include<conio.h>
using namespace std;
void speakPirate(string s);
int main()
{
string phrase;
cout << "Enter the phrase to Pirate-Ize: ";
getline(cin, phrase);
speakPirate(phrase);
_getch();
return 0;
}
void speakPirate(string s)
{
int found;
// list of pirate words
string pirate[12] = { "ahoy", "matey", "proud beauty", "foul blaggart", "scurvy dog", "whar", "be", "th'", "me", "yer", "galley", "fleabag inn" };
// list of normal words
string normal[12] = { "hello", "sir", "madam", "officer", "stranger", "where", "is", "the", "my", "your", "restaurant", "hotel" };
for (int i = 0; i < s.length(); i++)
{
found = s.find(normal[i]);
if (found > -1)
{
s.replace(found, found + pirate[i].length(), pirate[i]);
}
}
cout << s;
}
I'm not sure why, but this doesn't really work either. I also notice that when I try changing a larger word into a smaller word, some of the original word is leftover, for example:
Enter the phrase to Pirate-Ize: hello
ahoyo
And I just noticed that it sometimes might not even change the word at all, for example:
Enter the phrase to Pirate-Ize: where
where
How come? Could someone please tell me what I need to do or a more effective solution that I could implement? Thanks a lot.

Answer 1

Here you iterate over the length of the text:
for (int i = 0; i < s.length(); i++)
It should be the length of the array of texts, something like
for (int i = 0; i < 12; i++)
However, you should use a std::map to model the mapping between the normal words and their pirate version.
std::map<std::string, std::string> words = {
{"hello", "ahoy"},
// .. and so on
};
for(auto const & kvp : words)
{
// replace kvp.first with kvp.second
}

Answer 2

Marius is correct that the major error is that you need to iterate over the length of the arrays. A different way than mapping would be to use erase() and insert() where you used replace(). replace() does not account for the lengths of the strings being different, but removing a substring and then adding in a new substring will. This can be done as follows
for (int i = 0; i < 12; i++)
{
found = s.find(normal[i]);
// Locate the substring to replace
int pos = s.find( normal[i], found );
if( pos == string::npos ) break;
// Replace by erasing and inserting
s.erase( pos, normal[i].length() );
s.insert( pos, pirate[i] );
}