Vector search for matching string.

Hi,

Just working through a problem in Accelerated C++ and it's to determine if a string has been duplicated in a given vector. I have got the program to work and run but I also then get an error box stating "Debug Assertion Failed" - "Expression: vector subscript out of range".

The code is:

Code:

#include <vector>
#include <iomanip>
#include <iostream>
#include <ios>
#include <string>
#include <algorithm>

using namespace std;

int main()
{
	cout << "Please enter a list of words: ";
	
	vector<string> words;
	string data;

	while (cin >> data)
		words.push_back(data);

	typedef vector<string>::size_type vec_sz;
		vec_sz size = words.size();

	// sort vector into alphabetic order
		sort (words.begin(), words.end());

	//checks for any matching words in the vector
	
		for(int x = 0; x <= size; ++x)
		{
			if (words[x] == words[x + 1])
			{
				cout << "You have a matching pair of words: " << words[x] << " " << words[x+1];
			}

			else
			{
				cout << "No matches";
			}
		}

	

	system ("pause");

	return 0;

}

Any idea why I am getting that error message?

Thanks,

Darren.

By using x <= size as the loop condition, you will eventually attempt to access words[size], which does not exist. You should use x < size as the loop condition.

Originally Posted by laserlight

By using x <= size as the loop condition, you will eventually attempt to access words[size], which does not exist. You should use x < size as the loop condition.

Yes that's worked now thanks, although I have had to use x < size - 1 due to the vector indexing.

Thanks,

Darren.

You could also structure the loop like:

Code:

for (unsigned i = 1; i < size; ++i) {
    if (v[i-1] == v[i])...

It also looks like you are printing the message "No matches" in a wrong place.

Originally Posted by anon

You could also structure the loop like:

Code:

for (unsigned i = 1; i < size; ++i) {
    if (v[i-1] == v[i])...

It also looks like you are printing the message "No matches" in a wrong place.

Thanks I changed the location of the "no matches"/

Another question as well please:

If I now wanted to determine the string with the shortest number of characters and the one with the most, how would I go about doing that?

I know how to work out the size of the indiviual strings, however how would you compare them with the others in the vector to determine the shortest and longest?

Thanks

Originally Posted by darren78

Another question as well please:

If I now wanted to determine the string with the shortest number of characters and the one with the most, how would I go about doing that?

I know how to work out the size of the indiviual strings, however how would you compare them with the others in the vector to determine the shortest and longest?

Thanks

Generally you compare with < and/or >. You will not, of course, compare every string's size with every other string's size, but go through the vector one by one.