cu,m in C++

#include <iostream>
#include <string>
#include <boost/lexical_cast.hpp>

void Run( const std::string& v, int tgt, int start ) {
    for( ; tgt >= 2 * start + 1; ++start )
        Run( v + ' ' + boost::lexical_cast<std::string>( start ), tgt - start, start + 1 );
    std::cout << v << ' ' << tgt << std::endl;
}

int main() {
    Run( std::string(), 10, 1 );
    getchar();
}


Second paraphrasing is as follows:

#include <cassert>
#include <cstdlib>
#include <iostream>

class Cpu {
  public:
    virtual int dummy( int, int ) {}
  private:
    virtual int add_( int a, int b ) { return a + b; }  /* A */
    virtual int sub_( int a, int b ) { return a - b; }  /* B */
    virtual int mul_( int a, int b ) { return a * b; }  /* C */
    virtual int div_( int a, int b ) { return a / b; }  /* D */
    virtual int mod_( int a, int b ) { return a % b; }  /* E */
    virtual int and_( int a, int b ) { return a & b; }  /* F */
    virtual int or_( int a, int b )  { return a | b; }  /* G */
    virtual int xor_( int a, int b ) { return a ^ b; }  /* H */
};

int main( int argc, char* argv[] ) {
    typedef int (Cpu::*Memfun)( int, int );

    union {
        Memfun fn;
        unsigned char ptr[6];
    } u;

    Cpu    cpu;

    u.fn = &Cpu::dummy;

    assert( argc == 4 );

    int p1 = atoi( argv[ 1 ] );
    int p2 = atoi( argv[ 3 ] );
    char op = argv[2][0];

    assert( op >= 'A' && op <= 'H' );

    u.ptr[0] = 1 + 4 * ( op - 'A' + 1 );  // Don't look here!

    std::cout << "The answer is " << ( (cpu.*(u.fn))( p1, p2 ) ) << std::endl;
}

Third paraphrasing:

#include <cassert>
#include <cstdlib>
#include <iostream>

class Cpu {
  public:
    virtual int dummy( int, int ) {}
  private:
    virtual int add_( int a, int b ) { return a + b; }  /* A */
    virtual int sub_( int a, int b ) { return a - b; }  /* B */
    virtual int mul_( int a, int b ) { return a * b; }  /* C */
    virtual int div_( int a, int b ) { return a / b; }  /* D */
    virtual int mod_( int a, int b ) { return a % b; }  /* E */
    virtual int and_( int a, int b ) { return a & b; }  /* F */
    virtual int or_( int a, int b )  { return a | b; }  /* G */
    virtual int xor_( int a, int b ) { return a ^ b; }  /* H */
};

int main( int argc, char* argv[] ) {
    typedef int (Cpu::*Memfun)( int, int );

    union {
        Memfun fn;
        unsigned char ptr[6];
    } u;

    Cpu    cpu;

    u.fn = &Cpu::dummy;

    assert( argc == 4 );

    int p1 = atoi( argv[ 1 ] );
    int p2 = atoi( argv[ 3 ] );
    char op = argv[2][0];

    assert( op >= 'A' && op <= 'H' );

    u.ptr[0] = 1 + 4 * ( op - 'A' + 1 );  // Don't look here!

    std::cout << "The answer is " << ( (cpu.*(u.fn))( p1, p2 ) ) << std::endl;
}


Header:

int main () {
  int line = 1; // set the line (y coordinate) to 1 (first line)
  int p = 0; // set the position in the line (x coordinate) to 0.
  DIR dcur = EAST; // set the current direction to EAST... DIR is a int typedef
  /* ======== PROGRAM VARS ======== */
    stack <int> svar; // the program stack
  /* ============================== */
    if(isblank(getVarStr(file)[0]) || isnull(getVarStr(file)[0])) // if line[0] is empty or '\0'
      err("No initial insructions: Execution failed"); // throw error... err(const char*)
    bool string_mode = false; // not in string mode...
    while(true) { // program loop
      randSeed(); // invokes random seed: srand(time(NULL));
         char curp = seek(line, p); // char current cursor position
         if(!string_mode)
             setdir(&dcur, line, p); // set the direction based on curp... ^^^
           if(istrampoline(curp)) // if # symbol (means skip next call):
             jumpp(dcur, &line, &p); // *p+=2;
           else // if 'curp' is normal (not '#')
             nextp(dcur, &line, &p); //  ++*p
         trypush(seek(line, p), &svar); // if 'curp' is number 0-9: svar.push(curp-'0');
    /* ========================= parse 'curp' =============== */
   /* ... */