/*
	C++ style program

		use string, vector, sort(), iostream

	read or generate N strings
	optionally sort them


	- Bjarne Stroustrup - http://www.research.att/~bs

*/

#include<vector>
#include<iostream>
#include<fstream>
#include<iterator>
#include<algorithm>
#include<string>

using namespace std;


/*
	command line argument handling:

		prog 1		- read from cin and sort 

		prog 0		- read from cin (don't sort)

		prog 1 file	- read from file and sort

		prog 0 file	- read from file (don't sort)

		prog 1 file ofile - read from file, sort, and write to ofile

		prog 0 file ofile - read from file (don't sort) and write to ofile
		
	an optional 4th argument controls preallocation.
*/


int main(int argc, char* argv[])
{
	int max = 0;	// by default: read from cin
	int res = 1000;	// by default: grow incrementally
	bool s = true;	// by default: sort
	char* file = 0;
	char* ofile = 0;

	switch (argc) {	// s { max | file } res
	case 5:
		res = atoi(argv[4]);
	case 4:
		ofile = argv[3];
	case 3:
		max = atoi(argv[2]);
		if (max == 0) file = argv[2];
	case 2:
		s = atoi(argv[1]);
		break;
	default:
		cerr << "wrong number of arguments\n";
		exit(1);
	} 

	vector<string> buf;
	buf.reserve(res);	// logically redundant; for efficiency only

	string d;

	if (max) {
		cout << "generate " << max << endl;
	
	}
	else if (file) {
		fstream fin(file,ios::in);

		cout << "C++ style read of strings from " << file << endl;
		while(getline(fin,d)) buf.push_back(d);
	}
	else {
		cout << "C++ style read of strings from read cin\n";
		while(getline(cin,d)) buf.push_back(d);
	}

	if (s) {
		cout << "sort\n";	
		sort(buf.begin(),buf.end());
	}

	if (ofile) {
		cout << "write " << ofile << endl;
		fstream fout(ofile,ios::out);
		copy(buf.begin(),buf.end(),ostream_iterator<string>(fout,"\n"));
	}

}