framing.cpp

#include <iostream>
#include <vector>
#include <algorithm>

using std::vector;
using std::string;
using std::max;

string::size_type width(const vector<string>& v)
{
	string::size_type maxlen = 0;
	for(vector<string>::size_type i = 0; i != v.size(); ++i)
		maxlen = max(maxlen, v[i].size());
	return maxlen;
}

vector<string> frame(const vector<string>& v){
	vector<string> ret;
	string::size_type maxlen = width(v);
	string border(maxlen + 4, '*');

	//write the top border
	ret.push_back(border);

	//write each interior row, bordered by ansterisk and a space
	for (vector<string>::size_type i = 0; i != v.size(); ++i){
		ret.push_back("* " + v[i] + string(maxlen - v[i].size(), ' ')
						+ " *");
	}

	// write the bottom border
	ret.push_back(border);
	return ret;
}

vector<string> vcat(const vector<string>& top, 
				const vector<string>& bottom)
{
	//copy the top picture
	vector<string> ret = top;

	ret.insert(ret.end(), bottom.begin(), bottom.end());
	return ret;
}

vector<string> hcat(const vector<string>& left, 
				const vector<string>& right)
{
	vector<string> ret;

	//add 1 to leave a space between pictures
	string::size_type width1 = width(left) + 1;

	//indices to look at elements from left and right
	//respectively
	vector<string>::size_type i = 0, j = 0;

	while(i != left.size() || j != right.size())
	{
		//construct new string to hold characters from
		//both pictures
		string s;

		//copy a row from the left-hand side, if there is one
		if(i != left.size())
			s = left[i++];

		//pad to full width
		s += string(width1 - s.size(), ' ');

		//copy a row from the right-hand side, if there is one
		if( j != right.size())
			s += right[j++];

		//add s to the picture we're creating
		ret.push_back(s);
	}
	return ret;
}