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OK,
I have been stuck on this one for weeks:
I am trying to develope my own encrypter of text.
What I need is just a few examples of how to do this.
For example how would I do this in C++?
I want the user to be able to type in the text and have it encrypted.Code:'a' = 'b'
'b' = 't'
/n = 'y'
etc.......
best regards,
machewy
I don't think you can do that.
You can enter as a string, parse it, replace certain letters with others.
How would I do that???:confused:
String parse's and such have been covered many times before, a little research may prove to be all you need.
You're doing a simple substitution cypher - been around for well over a thousand years.
Create an array with the translation - make it as big as an ascii table. Create a loop to read in the input, convert to an ascii interger, and pull that from the char array you've set up.
additonally build a string from the translation and then you can write it to the screen or a file.
Translation back would work the same way - convert the chars into ascii values and use another array to pull the original characters back.
i.e 0 = 48 = j
j = 106 = 0
Use a 2d array.
I assume you know all about ASCII, and have an ASCII chart.
So, you need 3 arrays:
OrigString[]
EncString[]
Convert[]
The original character becomes a pointer (or index value) for the convert array.
From your example:
a = 97
b = 98
t = 116
And we know,
Convert[97] = 98 (97 points to 98)
Convert[98] = 116 (98 points to 116)
... You fill-in the rest.
In general,
EncString[n] = Convert[ OrigString[n] ]
Yeah, but they've only been doing it in C++ for about 100 years! :)Quote:
been around for well over a thousand years.
I'm still confused.
I got this far:
What should I do???:confused:PHP Code:#include <iostream.h>
#include <stdlib.h>
int main()
{
char OrigString[100];
char EncString[100];
char Convert[100];
Convert[97] = 98;
cin.getline(Convert, 100);
cout<<Convert;
system("PAUSE");
return 0;
}
Can someone write me up a quick example program to use as a reference?
Thanks:)
look at http://www.asciitable.com/ as you can see here ever single character has a numeric value attached to it. Now what you do it you take one character and you convert it to it's ascii value:
so now ascii holds the numerical value for the character x. Second you need a 2d array that has first the ascii value of the first/original character as it's index and then the ascii value of the encoded character:Code:char x = '\0';
int ascii = 0;
cin.get(x);
ascii = (int)x;
Please note that the encoded and original values were picked at random by me =].Code:
int Table[256] = { 35,
67,
........
79 };
Now following the above code given when you do something alike:
To decypher your code you can either build a new array that would have 1 stored in it's 35th element (following the above example) or you could have a for loop that goes through the original array and finds the encoded value and then uses the index as the decyphered value:Code:
char encoded = (char)Table[ascii];
-or-Code:
int Decode[256] = { ......
1, // 35th element
......
2, // 67th element
......
256, // 79th element
...... };
char original = (char)Decode[ (int)encoded ];
note that the first example with a new array takes more memory and that the second example with the for loop takes more CPU time. So it is up to you to decide which you value more...Code:
for(int i = 0; Table[i] != (int)encoded; i++)
{}
char original = (char)i;
Thanks so much!!!!!!:)
The only thing I am going to have to do now is play around with what you guys gave me.
Anymore suggestions?
Yes. Look up XOR, it may interest you.Quote:
Originally posted by Machewy
Thanks so much!!!!!!:)
The only thing I am going to have to do now is play around with what you guys gave me.
Anymore suggestions?