Hi, lets say i have a number like 9152 ...and its to be expanded as such : 11111111122222
(thats 9 ones and 5 twos)

so .. if i want to expand any given number ... the obvious quick solution is something like this..

Code:
string expand(string& input)
{
	string ret="";
	for(int i=0;i<input.length();i+=2)
	{
		int expand_amount = input[i] - '0';
		for(int j=0;j < expand_amount; ++j)
			ret+=input[i+1];
	}
	return ret;
}
but in this solution ... we do ret.length() string concats , I want to assume that this is horrible for inputs such as 9999999999.

Anyone have a solution to making this a bit more .....clever?

(probably avoiding string concats all together)