P

ROGRAMOWANIE I JĘZYK

C++

/

A

NALIZA PROGRAMÓW NR

2

Temat: Zmienne typu wskaźnikowego i referencyjnego - arytmetyka wskaźników

Zadanie
Wykonać analizę poniższych programów. Nie używając komputera obliczyć wartości zmiennych określonych
jako OUTPUT przy danych wejściowych INPUT. Sprawdzić wyniki uruchamiając odpowiedni kod programu
na komputerze.

Cześć 1: Struktury.

1.

// INPUT : wspolrzedne srodka okregu o2, (x,y) = (2.5, 3.0)
// promien okregu o2, r = 6
// OUTPUT : odl, L1, S2

const

double

pi = 3.14;

struct

okrag

{

double

x,y;

int

r;

} o1 = {1.5, 0.5, 5};

okrag o2;

cout <<

"Podaj wspolrzedne srodka oraz promien drugiego okregu ..."

<< endl;

cout <<

"x = "

; cin >> o2.x;

cout <<

"y = "

; cin >> o2.y;

cout <<

"r = "

; cin >> o2.r;

double

odl = sqrt( (o1.x-o2.x)*(o1.x-o2.x) + pow(o1.y-o2.y,2) );

double

L1,S2;

L1 = 2.0*pi*o1.r;
S2 = pi*o2.r*o2.r;

2.

// INPUT : -
// OUTPUT : suma.re, suma.im, iloczyn.re, iloczyn.im

struct

liczba_zespolona

{

double

re;

double

im;

} suma, iloczyn;

liczba_zespolona z,w = {2.0,-3.0};
z.re = -5.0;
z.im = 4.0;

// Obliczamy sume liczb zespolonych : z + w

suma.re = z.re + w.re;
suma.im = z.im + w.im;

// Obliczamy iloczyn liczb zespolonych : z * w

iloczyn.re = z.re*w.re - z.im*w.im;
iloczyn.im = z.im*w.re + z.re*w.im;

Cześć 2: Wskaźniki.

1.

// INPUT : adres zmiennej A = 1000, adres zmiennej B = 2000,
// adres zmiennej c = 3000
// OUTPUT : podac wartosci, ktore wypisze program

int

A,B,C=25;

int

* pA = &A, * pB = 0, * pC = 0;

A = 5; B = 12;

cout <<

"A = "

<< A << endl;

cout <<

"B = "

<< B << endl;

cout <<

"C = "

<< C << endl << endl;

cout <<

"pA = "

<< pA << endl;

cout <<

"pB = "

<< pB << endl;

cout <<

"pC = "

<< pC << endl << endl;

B = A + 10;
pB = &B;

cout <<

"B = "

<< B << endl;

cout <<

"pB = "

<< pB << endl << endl;

C = *pA + *pB;
pC = &C;

cout <<

"C = "

<< C << endl;

cout <<

"pC = "

<< pC << endl << endl;

2.

// INPUT : adres zmiennej a = 1200, adres zmiennej b = 3000,
// adres zmiennej c = 2000
// OUTPUT : podac wartosci, ktore wypisze program

int

a,b,c;

int

* ptr1 = &a, * ptr2 = &b;

a = 3; b = 10;
c = (a++) - (--b);

cout <<

"a = "

<< a << endl;

cout <<

"b = "

<< b << endl;

cout <<

"c = "

<< c << endl << endl;

cout <<

"*ptr1 = "

<< *ptr1 << endl;

cout <<

"*ptr2 = "

<< *ptr2 << endl << endl;

*ptr1 = c + 20;
ptr2 = &c;

cout <<

"ptr1 = "

<< ptr1 << endl;

cout <<

"*ptr1 = "

<< *ptr1 << endl << endl;

cout <<

"c = "

<< c << endl;

cout <<

"*ptr2 = "

<< *ptr2 << endl;

Cześć 3: Referencje.

1.

// INPUT : -
// OUTPUT : podac wartosci, ktore wypisze program

int

x = 4, y = 7;

int

&ref_x = x;

int

&ref_y = y;

cout <<

"x = "

<< x << endl;

cout <<

"y = "

<< y << endl;

cout <<

"ref_x = "

<< ref_x << endl;

cout <<

"ref_y = "

<< ref_y << endl << endl;

ref_x = (++y) - 10;
cout <<

"x = "

<< x << endl;

cout <<

"ref_y = "

<< ref_y << endl << endl;

2.

// INPUT : -
// OUTPUT : podac wartosci, ktore wypisze program

int

x = 4, y, z = 12;

int

&ref_x = x;

int

&ref_z = z;

cout <<

"x = "

<< x << endl;

cout <<

"z = "

<< z << endl;

cout <<

"ref_x = "

<< ref_x << endl;

cout <<

"ref_z = "

<< ref_z << endl << endl;

int

&ref = y;

ref = (ref_x < z) ? 3:30;

cout <<

"y = "

<< y << endl;

cout <<

"ref = "

<< ref << endl << endl;

ref_x = (--z) - (ref++);
cout <<

"x = "

<< x << endl;

cout <<

"y = "

<< y << endl;

cout <<

"z = "

<< z << endl;

cout <<

"ref_x = "

<< ref_x << endl;

cout <<

"ref = "

<< ref << endl;

cout <<

"ref_z = "

<< ref_z << endl << endl;

Cześć 4: Arytmetyka wskaźników.

1.

// INPUT : adres pierwszego elementu tablicy jest rowny 1000
// OUTPUT : podac wartosci, ktore wypisze program

int

A[6] = {2, 4, 6, 8, 10, 12};

int

* pA0, * pA1;

int

diff;

pA0 = &A[0];
pA1 = A;
cout <<

"A[0] = "

<< A[0] << endl;

cout <<

"pA0 = "

<< pA0 << endl;

cout <<

"pA1 = "

<< pA1 << endl << endl;

pA0 = pA0++;
pA1 = pA1 + 4;
cout <<

"pA0 = "

<< pA0 << endl;

cout <<

"pA1 = "

<< pA1 << endl << endl;

diff = pA1 - pA0;
cout <<

"pA1 - pA0 = "

<< diff << endl;

2.

// INPUT : adres pierwszego elementu tablicy jest rowny 2000
// OUTPUT : podac wartosci, ktore wypisze program

double

A[6] = {2, 4, 6, 8, 10, 12};

double

* ptrA;

ptrA = &A[0];

// Tablica w wersji pierwszej

for

(

int

i=0; i<=5; i++)

cout <<

"A["

<< i <<

"] = "

<< A[i] << endl;

cout << endl;

// I - Operacje na tablicy A

for

(

int

i=0; i<=5; i++)

*(A + i) = A[i] + 5;

for

(

int

i=0; i<=5; i++)

cout <<

"A["

<< i <<

"] = "

<< A[i] << endl;

cout << endl;

// II - Operacje na tablicy A

for

(

int

i=0; i<=5; i++)

ptrA[i] = A[i] + 10;

for

(

int

i=0; i<=5; i++)

cout <<

"A["

<< i <<

"] = "

<< A[i] << endl;

cout << endl;

// III - Operacje na tablicy A

for

(

int

i=0; i<=5; i++)

*(ptrA + i) = A[i] - 1;

for

(

int

i=0; i<=5; i++)

cout <<

"A["

<< i <<

"] = "

<< A[i] << endl;

cout << endl;

3.

// INPUT : adres pierwszego elementu tablicy jest rowny 1500
// OUTPUT : podac wartosci, ktore wypisze program

double

A[6] = {2, 4, 6, 8, 10, 12};

double

* ptr1, * ptr2, * ptr3;

int

diff1,diff2;

ptr1 = A;
ptr2 = &A[2];
ptr3 = &A[5];

cout <<

"ptr1 = "

<< ptr1 << endl;

cout <<

"ptr2 = "

<< ptr2 << endl;

cout <<

"ptr3 = "

<< ptr3 << endl << endl;

cout <<

"*ptr1 = "

<< *ptr1 << endl;

cout <<

"*ptr2 = "

<< *ptr2 << endl;

cout <<

"*ptr3 = "

<< *ptr3 << endl << endl;

for

(

int

i=3; i<=5; i++)

*(ptr1 + i) = A[i] + 10;

for

(

int

i=3; i<=5; i++)

cout <<

"*(ptr1 + "

<< i <<

") = "

<< *(ptr1 + i) << endl;

cout << endl;

for

(

int

i=0; i<=5; i++)

cout <<

"A["

<< i <<

"] = "

<< A[i] << endl;

cout << endl;

ptr3 = ptr3 - 1;
diff1 = ptr3 - ptr1;

cout <<

"ptr3 = "

<< ptr3 << endl;

cout <<

"*ptr3 = "

<< *ptr3 << endl;

cout <<

"diff1 = ptr3 - ptr1 = "

<< diff1 << endl << endl;

ptr2 = ptr2 + 3;
diff2 = ptr2 - ptr1;

cout <<

"ptr2 = "

<< ptr2 << endl;

cout <<

"*ptr2 = "

<< *ptr2 << endl;

cout <<

"diff2 = ptr2 - ptr1 = "

<< diff2 << endl << endl;