Take Any String and save its permutations in a file

C++ : String Permutations

#include <string.h>
#include <iostream>
#include <fstream>
using namespace std;

class Permute{
	int start,end,count;
	char *f,*str;
public:
	Permute(char* st,char* fn){ // fn =  file name / full path with name
		start=0;
		end=strlen(st)-1;
		f=new char [strlen(fn)+1];
		strcpy(f,fn);
		str=new char [end];
		strcpy(str,st);
		count=0;
		//Worker(st,start,end);
	}
	void setstart(int s){ // set starting position
		start=s-1;
	}
	void setend(int e){ // set ending position
		end=e-1;
	}
	void Calcuate(void){
		cout<<"\n:: Creating Permutations of word "<<str<<" ::\n";
		cout<<"Processiong Entries Saved  ";
		Worker(str,start,end);
		cout<<count;
		cout<<"\n Permutation are Saved in file "<<f<<"\n";
	}
	void swap(char *fir, char *sec){ // swap characters of char array/string
		char temp = *fir;
		*fir = *sec;
		*sec = temp;
	}

	/* it is Basically Solved By Backtracking check this link 
		it is very high level technique with simple logic , 1 or more character will remains same and rest
		will iterate and swap, 
		"IT IS DONE BY RECURSION !" , if abcd is converted to abdc the it will backtrack it as abcd again !!
		same as Push/Pop in stack , it is specially written for Habeel and SAAD
	*/
	void Worker(char *a, int s, int e) { // 
		int it; //iterator
		if (s == e){
			Saveit(a);
		}
		else{
			for (it = s; it <= e; it++){
			  swap((&a[s]), (&a[it]));
			  Worker(a, s+1, e);
			  swap((&a[s]), (&a[it])); //backtrack
			}
		}
	} 
	void Saveit(char* arr){ // saving string to file
		ofstream out;
		out.open(f,ios::app);
		out<<arr<<"\n";
		out.close();
		/*system("CLS");
		cout<<"Processiong Entries Saved  ";
		count++;
		cout<<count;*/
		count++;
	}
	~Permute(void){
		delete [] f;
	}

};



int main(){ // Written By : Zulqurnain jutt
    char t[] = "ABC";
	Permute p(t,"Permute.txt");
	p.Calcuate();
    return 0;
}