// Martin Sewell <M.Sewell@cs.ucl.ac.uk>
// 28 November 2007
// Usage: libsvmformat inputfilename (outputfilename)

#include <iostream>
#include <fstream>
#include <sstream>

using namespace std;

int main(int argc, char *argv[]) {
	int n;
	double data;
	string inputlinestring;
	char * inputfilename;
	char * outputfilename;

	if (argc == 2 or argc == 3) {
		inputfilename = argv[1];
		if (argc == 2) {
			char * appendage = "f";
			outputfilename = (char*) malloc((strlen(argv[1]) + strlen(appendage) + 1)*sizeof(char));
			if (outputfilename == NULL) {
				printf("Problem with memory allocation.\n");
				return -1;
			}
			strcpy(outputfilename, argv[1]);
			strcat(outputfilename, appendage);
		}

		if (argc == 3) {
			if (strcmp(argv[1], argv[2]) == 0) {
				printf("Filenames must be distinct.\n");
				return -1;
			}
			outputfilename = (char*) malloc((strlen(argv[2]) + 1)*sizeof(char));
			if (outputfilename == NULL) {
				printf("Problem with memory allocation.\n");
				return -1;
			}
			strcpy(outputfilename, argv[2]);
		}

		ifstream inputfile(inputfilename);
		if (!inputfile) {
			cout << "Failed to open input file.";
			return -1;
		}

		ofstream outputfile(outputfilename);
		if (!outputfile) {
			cout << "Failed to open output file.";
			return -1;
		}

		while (!inputfile.eof( )) {
			while (getline(inputfile, inputlinestring)) {
				istringstream inputlinestream (inputlinestring);
				n = 0;
				while (inputlinestream >> data) {
					n = n + 1;
					outputfile << " " << n << ":" << data;
				}
				outputfile << endl;
			}
		}

		inputfile.close();
		outputfile.close();
		free(outputfilename);
	
		cout << "Success!" << endl;
		system("PAUSE");
	}
	else
		cout << "Usage: libsvmformat inputfilename (outputfilename)" << endl;
}