File encryption and decryption algorithm C ++ txt word

# Include <stdio. h>
# Include <stdlib. h>
Int main ()
{
Int jiajie_fun (char infile [20], char outfile [20]); // Declaration of the encryption and decryption Function
Int choose;
Char mingfile [20];
Char mifile [20];
Printf ("welcome to the encryption and decryption File System \ n ");
While (1)
{
Printf ("Enter number 1 and press enter to enter the encryption system \ n ");
Printf ("Enter number 2 and press enter to enter the decryption system \ n ");
Printf ("select and enter 1 or 2 \ n ");
Scanf ("% d", & choose );
If (choose = 1 | choose = 2) break;
Printf ("if you have not entered the correct one, enter 1 or 2 and press enter to end. Please enter \ n" again ");
}
If (choose = 1)
{
Printf ("enter the name of the file you want to encrypt and press enter to end \ n ");
Scanf ("% s", mingfile );
Printf ("Enter the encrypted target file name and press enter to end \ n ");
Scanf ("% s", mifile );
Jiajie_fun (mingfile, mifile );
Printf ("the % s file has been encrypted successfully. Thank you for using this program \ n", mingfile );
}

If (choose = 2)
{
Printf ("enter the name of the file you want to decrypt and press enter to end \ n ");
Scanf ("% s", mifile );
Printf ("Enter the target file name to be decrypted, and press enter to end \ n ");
Scanf ("% s", mingfile );
Jiajie_fun (mifile, mingfile );
Printf ("decryption of the % s file has been successful. Thank you for using this program \ n", mifile );

}
Getchar ();
Getchar ();

}

Int jiajie_fun (char infile [20], char outfile [20])
{
Int key = 50; // 0 the number of digits that cannot be encrypted is not safe. However, in my personal opinion, the length is not the length, but the complexity determines the security.
// Float key = 3.14; // Replace the key if necessary
// Char key [] = "I am a goodboy ";
FILE * in, * out;
Char ch;

If (in = fopen (infile, "rb") = NULL)
{Printf ("this file \ n cannot be found ");
Exit (0);} // end the program
If (out = fopen (outfile, "wb") = NULL)
{Printf ("this file \ n cannot be found ");
Exit (0 );}

While (1)
{
Ch = fgetc (in );
Ch = ch ^ key; // It is good to use other more complex formulas here.
If (feof (in) break;
Fputc (ch, out );
}

Fclose (in );
Fclose (out );
Return 0;
}
// ********************************* Unique or encryption and decryption *** *******************************//
// ******************************** Embedded into File Reading **** **************************//
/* # Include <stdio. h>
Void main ()
{
Char ming [13] = "I am goodboy"; // '\ 0' plaintext
Int miyao = 356; // key
Char secret [13]; // The ciphertext size must be specified
For (int I = 0; I <13; I ++)
{* (Secret + I) = miyao ^ (* (ming + I);} // Encryption
Printf ("% s \ n", secret );
For (I = 0; I <13; I ++)
{* (Ming + I) = miyao ^ (* (secret + I);} // decrypt
Printf ("% s \ n", ming );
}*/