Edit distance calculation [ C++ ]

edit_distance.cpp

#include <iostream>
#include "edit_distance.h"

using namespace std;

// public
EditDistance::EditDistance(char *string1, char *string2){
	s1 = string1;
	s2 = string2;
	rows = strlen(s1)+1;
	columns = strlen(s2)+1;
	allocate_range();
	vagner_fisher_calc();
}

void EditDistance::vagner_fisher_view(){
	cout << "Calculated rows: " << s1 << " Calculated columns: " << s2 << endl;
	for(int i = 0; i<rows; i++){
		for(int j = 0; j<columns; j++){
			cout << range[i][j] << ' ';
		}
		cout << endl;
	}
}

int **EditDistance::get_range_matrix(){
	return range;
}

int EditDistance::get_range(){
	return range[rows-1][columns-1];
}

// private
void EditDistance::allocate_range(){
	range = new int*[rows];
	for(int i = 0; i<rows; i++){
		range[i] = new int[columns];
	}
}

int EditDistance::compare_symbs(char a, char b){
	return (a==b)?0:1;
}

void EditDistance::vagner_fisher_calc(){
	for(int j = 0; j<columns; j++){
		range[0][j] = j;
	}
	for(int i = 0; i<rows; i++){
		range[i][0] = i;
	}
	for(int i = 1; i<rows; i++){
		for(int j = 1; j<columns; j++){
			range[i][j] = min(min(range[i][j-1]+1, range[i-1][j]+1), range[i-1][j-1] + compare_symbs(s1[i-1],s2[j-1]));
		}
	}
}

edit_distance.h

class EditDistance {
private: 
	const char *s1;
 	const char *s2;
 	int **range;
 	int rows,columns;


 	void allocate_range();
 	void vagner_fisher_calc();
 	int compare_symbs(char, char);
public:
	EditDistance(char *, char *);
	~EditDistance();
  
	void vagner_fisher_view();
	int **get_range_matrix();
	int get_range();
};