2016-Programmieren in C/ C++

Was fehlt?

______ small_to_large(const void * first, const void * second)
{
    assert(first != NULL);
    assert(second != NULL);
    
    IntUlongPair *a = (IntUlongPair *) first;
    IntUlongPair *b = (IntUlongPair *) second;
    
    if(a->first > b->first)
    {
        return 1;
    }
    else if(a->first < b->first)
    {
        return -1;
    }
    else
    {
        if(a->second < b->second)
        {
            return 1;
        }
        else
        {
            return -1;
        }
    }
}

void sort_int_ulong_pairs(IntUlongPair *tab, unsigned long len)
{
    assert(tab != NULL);
    
    qsort((void *) tab, len, sizeof(*tab), &small_to_large);
}

Was ist richtig?

C++

Wie kann man auf alle Elemente eines Containers zugreifen?

Nennen Sie die zwei Präprozessor-Variablen, die für den Dateinamen und für die Zeile in der Datei stehen?

Was wird  'asserted'?

int small_to_large(const void * first, const void * second)
{
    assert(_______);
    assert(_______);
    
    IntUlongPair *a = (IntUlongPair *) first;
    IntUlongPair *b = (IntUlongPair *) second;
    
    if(a->first > b->first)
    {
        return 1;
    }
    else if(a->first < b->first)
    {
        return -1;
    }
    else
    {
        if(a->second < b->second)
        {
            return 1;
        }
        else
        {
            return -1;
        }
    }
}

void sort_int_ulong_pairs(IntUlongPair *tab, unsigned long len)
{
    assert(tab != NULL);
    
    qsort((void *) tab, len, sizeof(*tab), &small_to_large);
}

Was fehlt?

int small_to_large(const void * first, const void * second)
{
    assert(first != NULL);
    assert(second != NULL);
    
    _______*a = (_______*) first;
    _______*b = (_______*) second;
    
    if(a->first > b->first)
    {
        return 1;
    }
    else if(a->first < b->first)
    {
        return -1;
    }
    else
    {
        if(a->second < b->second)
        {
            return 1;
        }
        else
        {
            return -1;
        }
    }
}

void sort_int_ulong_pairs(IntUlongPair *tab, unsigned long len)
{
    assert(tab != NULL);
    
    qsort((void *) tab, len, sizeof(*tab), &small_to_large);
}

Was ist richtig?

int small_to_large(const void * first, const void * second)
{
    assert(first != NULL);
    assert(second != NULL);
    
    IntUlongPair *a = (IntUlongPair *) first;
    IntUlongPair *b = (IntUlongPair *) second;
    
    if(a->first > b->first)
    {
        return __;
    }
    else if(a->first < b->first)
    {
        return __;
    }
    else
    {
        if(a->second < b->second)
        {
            return __;
        }
        else
        {
            return -1;
        }
    }
}

void sort_int_ulong_pairs(IntUlongPair *tab, unsigned long len)
{
    assert(tab != NULL);
    
    qsort((void *) tab, len, sizeof(*tab), &small_to_large);
}

Was fehlt?

int small_to_large(const void * first, const void * second)
{
    assert(first != NULL);
    assert(second != NULL);
    
    IntUlongPair *a = (IntUlongPair *) first;
    IntUlongPair *b = (IntUlongPair *) second;
    
    if(a->first > b->first)
    {
        return 1;
    }
    else if(a->first < b->first)
    {
        return -1;
    }
    else
    {
        if(a->second < b->second)
        {
            return 1;
        }
        else
        {
            return -1;
        }
    }
}

void sort_int_ulong_pairs(IntUlongPair *tab, unsigned long len)
{
    assert(tab != NULL);
    
    qsort((void *) tab, len, sizeof(*tab), _________);
}

Was muss verändert werden?

const unsigned long * logsearch_sm_geq(const unsigned long *leftptr,
                                            const unsigned long *rightptr,
                                            unsigned long key)
  {
1    const unsigned long *midptr;
2    const unsigned long *end = rightptr;
3   
4    while(leftptr <= rightptr)
5    {
6        midptr = leftptr + (unsigned long) (rightptr - leftptr)/2;
7        if(key < *midptr)
8        {
9            rightptr = midptr - 1;
10        }
11        else
12        {
13            if(key > *midptr)
14            {
15               leftptr = midptr + 1;
16            }
17            else
18            {
19                {
20                    return midptr;
22                }
23            }
24        }
25    }
26    return NULL;
    }

Consider a complex number c and the series z0, z1, z2, . . . of complex
numbers, where
z_0 = 0
z_n+1 = z_n *z_n + c
The Mandelbrot set M is the set of all complex numbers c such that

Erkläre gelb Markiertes!

static unsigned long mandelbrot_iter ( const Complex c,
unsigned long nmax )
{
Complex z = c;
unsigned long n;
for (n = 0; n < nmax ; n++)
{
const double a = z.real ,
b = z. imag ;
if (a * a + b * b > 4.0) /* |z| > 2 */
{ /* equiv . to sqrt (a * a + b * b) > 2.0 */
return n;
}

z. real = a * a - b * b + c. real ; /* z = z * z + c */
z. imag = 2.0 * a * b + c. imag ;
}
return nmax ;
}

Erkläre gelb Markiertes!

static unsigned long mandelbrot_iter ( const Complex c,
unsigned long nmax )
{
Complex z = c;
unsigned long n;
for (n = 0; n < nmax ; n++)
{
const double a = z.real ,
b = z. imag ;
if (a * a + b * b > 4.0) /* |z| > 2 */
{ /* equiv . to sqrt (a * a + b * b) > 2.0 */
return n;
}

z. real = a * a - b * b + c. real ; /* z = z * z + c */
z. imag = 2.0 * a * b + c. imag ;
}
return nmax ;
}

Was fehlt?

static void estimate_size_of_area ( unsigned long maxsteps )
{
unsigned long steps ;
for ( steps = 1; steps <= maxsteps ; steps *= 10)
{
unsigned long s, inside = 0;
for (s = 0; s < steps ; s++)
{
double a = _______; /* random in range [0 ,1) */
double b = _______; /* random in range [0 ,1) */
if ( inside_area (a,b))
{
inside ++;
}
}
printf (" steps  = %9lu ,  inside  = %9lu ,  ratio  =  %.6f\n",
steps , inside ,( double ) inside / steps );
}

Approximation of line integrals

\( {\sum^k_{i=1} \sqrt{d^2 + ( f(start*d*i)-f(start*d*(i-1)))^2}} \)

static double approx_line_length ( double (*f)( double ),
double start , double stop ,
unsigned long k)
{
what's first?
for (i = 1; i <= k; i++)
{
double fx2 = f(x1 + dx), /* x1 + dx = start + d * i */
dy = fx2 - fx1;
total += sqrt ( dx_square + dy * dy );
fx1 = fx2; /* reuse fx2 as fx1 in next iteration */
x1 += dx; /* x1 becomes start + d * i */
}
return total ;
}

Approximation of line integrals

\( {\sum^k_{i=1} \sqrt{d^2 + ( f(start*d*i)-f(start*d*(i-1)))^2}} \)

static double approx_line_length ( double (*f)( double ),
double start , double stop ,
unsigned long k)
{

double total = 0.0 , x1 = start , fx1 = f( start );
const double dx = ( stop - start )/k, dx_square = dx * dx;
unsigned long i;

for (i = 1; i <= k; i++)
{
what now?
}
return total ;
}

Simulation of a game

Was fehlt?

static Score play_single_game ( bool silent , size_t start_cash ,
size_t threshold )
{
Score score ;
______ = start_cash ;
for ( score . throws = 1;
score . cash > 0 && score . cash <= threshold ;
score . throws ++)
{
size_t dice1 , dice2 ;
score .cash --; /* player pays one unit */
dice1 = 1 + drand48 () * 6; /* simulation : roll 1st dice */
dice2 = 1 + drand48 () * 6; /* simulation : roll 2nd dice */
if ( dice1 + dice2 == 12) score . cash += 6;
else
{
if ( dice1 + dice2 >= 8) score . cash += 2;
}
if (! silent )
printf ("%3 lu  throw %c |%*s*\n",score .throws ,
score . throws == 1 ? ’ ’ : ’s’,
(int) score .cash ,"");
/* show * with indendation of width = cash */
}
return score ;
}

Simulation of a game

Was fehlt?

static Score play_single_game ( bool silent , size_t start_cash ,
size_t threshold )
{
Score score ;
score . cash = start_cash ;
for ( ________ = 1;
score . cash > 0 && score . cash <= threshold ;
_______++)
{
size_t dice1 , dice2 ;
score .cash --; /* player pays one unit */
dice1 = 1 + drand48 () * 6; /* simulation : roll 1st dice */
dice2 = 1 + drand48 () * 6; /* simulation : roll 2nd dice */
if ( dice1 + dice2 == 12) score . cash += 6;
else
{
if ( dice1 + dice2 >= 8) score . cash += 2;
}
if (! silent )
printf ("%3 lu  throw %c |%*s*\n",score .throws ,
score . throws == 1 ? ’ ’ : ’s’,
(int) score .cash ,"");
/* show * with indendation of width = cash */
}
return score ;
}

Simulation of a game

Was fehlt?

static Score play_single_game ( bool silent , size_t start_cash ,
size_t threshold )
{
Score score ;
score . cash = start_cash ;
for ( score . throws = 1;
score . cash > 0 && score . cash <= threshold ;
score . throws ++)
{
size_t dice1 , dice2 ;
score .cash --; /* player pays one unit */
dice1 = 1 + ________ * 6; /* simulation : roll 1st dice */
dice2 = 1 + ________ * 6; /* simulation : roll 2nd dice */
if ( dice1 + dice2 == 12) score . cash += 6;
else
{
if ( dice1 + dice2 >= 8) score . cash += 2;
}
if (! silent )
printf ("%3 lu  throw %c |%*s*\n",score .throws ,
score . throws == 1 ? ’ ’ : ’s’,
(int) score .cash ,"");
/* show * with indendation of width = cash */
}
return score ;
}

Simulation of a game

Was fehlt?

static Score play_single_game ( bool silent , size_t start_cash ,
size_t threshold )
{
Score score ;
score . cash = start_cash ;
for ( score . throws = 1;
score . cash > 0 && score . cash <= threshold ;
score . throws ++)
{
size_t dice1 , dice2 ;
score .cash --; /* player pays one unit */
dice1 = 1 + drand48 () * 6; /* simulation : roll 1st dice */
dice2 = 1 + drand48 () * 6; /* simulation : roll 2nd dice */
if ( dice1 + dice2 == 12) score . cash += 6;
else
{
if ( dice1 + dice2 >= 8) score . cash += 2;
}
if (! silent )
printf ("%3 lu  throw %c |%*s*\n",score .throws ,
score . throws == 1 ? ’ ’ : ’s’,
(int) score .cash ,"");
/* show * with indendation of width = cash */
}
______ _______ ;
}

Schreib in C++ ein Funktionstemplate getmin für die Berechnung des Minimums von zwei Werten, deren Typ als Template-Parameter deklariert wird.

Implementieren Sie in C++ eine template-basierte Funktion distance_template‚ die vier Parameter x1, y1, x2, y2 eines unbekannten aber gleichen numerischen Typs erhält. Diese repräsentieren zwei Punkte (x1,y1) und (x2,y2) im Euklidschen Raum. Die genannte Funktion soll die Distanz der beiden Punkte als double-Wert liefern.