Friday, February 28, 2003

Reviewed the solutions to the midterm exam written last week.

Using library algorithms (K&M Chapter 6)

Splitting a string into its constituent words:

#include <algorithm>
#include <cctype>
#include <string>
#include <vector>

#include "split.h"

using std::find_if;
using std::string;
using std::vector;

using std::isspace;

// `true' if the argument is whitespace, `false' otherwise
bool space(char c)
{
	return isspace(c);
}

// `false' if the argument is whitespace, `true' otherwise
bool not_space(char c)
{
	return !isspace(c);
}

vector<string> split(const string& str)
{
	typedef string::const_iterator iter;
	vector<string> ret;

	iter i = str.begin();
	while (i != str.end()) {

		// ignore leading blanks
		i = find_if(i, str.end(), not_space);

		// find end of next word
		iter j = find_if(i, str.end(), space);

		// copy the characters in [i, j)
		if (i != str.end())
			ret.push_back(string(i, j));
		i = j;
	}
	return ret;
}

Last modified: Tue Mar 4 02:04:08 2003