C++ :: How To Calculate And Apply All Char Combinations

how to write a password cracking program that will try all possible char combinations for just two chars (without duplicating any combination guesses). Obviously, there would only be 4 possible truth table combinations for two boolean values, but how would a person calculate the number of all possible combinations for two values with 70 different possible chars?

#include <iostream>
#include <string>
#include <cstdlib>
#include <ctime>
using namespace std;
static const char alphanum[] =
"0123456789"
"!@#$%^&*"
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz";
/*

Boolean Truth Table for two values:

p q
-----
T T
T F
F T
F F

Note that there are 70 chars in all specified above.

It will require much more than a simple truth table to try every possible char combination (especially if the password to be cracked is 2 or more chars). Using this guy's code: [URL] ..... as a starting point, I'm writing a program that will crack a password with a length of just 2 chars.

*/
int stringLength = 2;
char genRandom() {
return alphanum[rand() % stringLength];
}
int main() {
std::string password = "Sp";
srand(time(0));
std::string Str;

[code]....