encryption/ decryption without key using C++

#include<iostream>//for cin , cout.
using namespace std;
#include<iomanip>// for setw().
#include<windows.h>//for set_color(); ,clear_screen();.
#include<conio.h>//for getche().

int main()// main function.
{
	char enc[2000];//the string for the text.
	int count,i,j;//for loop counter.
	char choise,cho='y';//do while variable.
	char temp;
	do
	{
		cout<<setw(40)<<"Enter the text which you want to encrypt: \n\n\t";
		if(cin.peek() == '\n') 
		cin.get(); // add this line
		cin.get(enc, 2000);
		cout<<setw(20)<<"(e) to encrypt .\n(d) to decrypt .\n(x) to exit.\n\a ";
		cin>>choise;
		if(choise=='e'||choise=='E')
		{
			
			for(i=0,j=strlen(enc)-1;i<strlen(enc)/2;i++,j--)
			{
					
					temp=enc[j];
					enc[j]=enc[i];
					enc[i]=temp;
			}

			for(count=0;count<strlen(enc);count++)
			{	
				if(enc[count]+count>255)
					enc[count]=enc[count]-255+count;
				else
					enc[count]+=count;
			}
	
			cout << "Encrypted Text is: " << enc << endl;

		}
		else if(choise=='x'||choise=='X')
			return 0;
		else if(choise=='d'||choise=='D')
		{

	

			for(count=1;count<strlen(enc);count++)
			{
			if(enc[count]-count<0)
				enc[count]=enc[count]+(255-count);
			else
				enc[count]-=count;
			}

			for(i=0,j=strlen(enc)-1;i<strlen(enc)/2;i++,j--)
			{
					
					temp=enc[i];
					enc[i]=enc[j];
					enc[j]=temp;
			}
			cout<<enc<<endl;
		}
		else
		{
			cout<<"please ,enter :\n(e) to encrypt .\n(d) to decrypt .\n(x) to exit.\n "; 
		}
		cout<<"Do you want to continue?(y/n) ";
		cin>>cho;
	}while((cho=='y')||(cho=='Y'));

	return 0;
}