20. 10 , .
21. ' , b, c .
ϳ:
22. ' R (, ).
ϳ: :
23. ' .
24. ϳ
, .
25.
i.
2 C ̲ ̲ ²
2.1 ֳ
, .
2.2
, , , .
, , .
2.1 y = axi2 sin xi, x1=-1, x2=-0,93, x3=-0,49, x4=0, x5=1,13, x6=0,96, x7=1,75.
' ', . , ' (), . , . ' ' ', .
x[n] (n =7). . 0 n 1. , .
:
// P2_1.CPP -
//
#include <iostream>
|
#include <math.h>
Using namespace std;
Void main()
{
const int n =7;
float x[n];
Int i;
Float a, y;
//
cout<< " :" <<endl;
for (i=0; i < n; i++)
{
cout << "x [" << i << "] = ";
|
|
cin >> x [ i ];
cout << x [ i ] << endl;
}
a = 10.5;
//
for (i = 0; i < n; i++)
{
y = a*x [ i ] * x [ i ] sin (x [ i ]); cout << " =" << x[i]
<< "y = " << y << endl;
}
}
float x [n], ' ', .
, , cin >> x [i];, cout << "x [" << i << "] = "; x[i], .
cin >> x[i]; , , , ' x[i] Enter, . , f or, n , .
++ , float x[7] (n =7) x[0], x[1], x[2] x[6] x[0] , x[1] .. : , . ֳ , :
// 2_2.CPP
//
#include < math.h>
#include < iostream>
Using namespace std;
Float a, y;
Void main ()
{
const int n =7;
float x [ n ];
Int i;
Float a, y;
a = 10.5;
for (i = 0; i < n; i++)
{
cout << "x [ " << i << "] = ";
cin >> x [ i ];
y = a * x[ i ]*x[ i ] - sin(x[ i ]);
cout << " =" << x[] << " y= " << y << endl;
}
}
2.2 10 , .
mas[i] (i=0..9), , , :
// 2_3.CPP
//
#include < math.h >
#include < iostream>
Using namespace std;
Void main ()
{
const int n = 10; //
float mas[n]; //
Int i, k;
Float s;
s = 0; // s -
k = 0; // k -
for (i=0; i < n; i++)
{
cout << " mas [ " << i << "] = ";
cin >> mas [ i ];
cout << mas [ i ] << endl;
s = s + mas [ i ];
if (mas[ i ] = = 5)
k =k+1;
}
cout << " = " << s / float(n) << endl;
cout << "ʳ =" << k<< endl;
|
|
}
s , k . .
cout << " mas [ " << i << "] = ";
, (cout << " "<< s / float (n) << endl; cout << "ʳ =" <<k<< endl;).
, , , . . , . , :
̳ , .
. , [1] [2] , , -20.5 ( 0). -, : , - .
2.3 M 10.
// 2_4.CPP
// 10.
#include < iostream>
Using namespace std;
Void main ()
{
const int n = 3; //
const int m = 5; //
float M [ n] [m];
Int i, k;
Float s;
s = 10;
cout << " :" << endl;
//
for (i = 0; i < n; i++)
for (k = 0; k < m; k ++)
{
cout << " M [ " << i << "] = " << "[ " << k << ]";
cin >> M [ i ] [ k ];
cout << M [ i ] [ k ] << endl;
M [ i ] [ k ] = M [ i ] [ k ] + s; // M [ i ] [ k ] + = s;
}
cout << " :" << endl;
//
for (i = 0; i < n; i++)
{
cout << endl;
for (k = 0; k < m; k++)
cout << M [ i ] [ k ] << " ";
}
}
float M[n][m];
, , .
, , . i k.
' , .
2.3
++ , .
, ', . , , (). ֳ : , , .. - , , ' .
:
* ';
, ;
' ' -;
* , "" .
:
int *pn; // ;
|
|
float *pf1, *pf2; // ;
' - - . NULL, "" .
++ , :
& " ";
* " ".
" * ", , , , .
" & ", , , .
:
<> *ptr;
<> *ptr = < - >;
<> *ptr =&<' >; //
:
int *ptx,b; float y; // - ptx b y;
float *sp = &y; // sp y
float *p = sp; // p ( ),
// sp, y.
" * " ' - , , :
long * pt; long* Uk; int * ki, x, h; //
, void, :
void *p, *pt; //
, ' - , , .
, , ' "*", :
int *p, *p1; // ' int;
int x =12, y=5, m [7 ]; // x,y m,
// x,y
p = &y; // p y.
, :
cout << " " << p << " = " <<*p;,
', y ( 5).
x = *p;, x=5, *p = y = 5;.
y :
y = 10; // *p = 10;
* p= * p+5; // y = y + 5; y = 15.
, (), ' (), ' (), 0 ( ),:
int *pt = (char *) 0x00147; //
int *arrpt = new int [10]; //
//
har *p = 0; //
, " * ", , :
float *pt1, *pt2, x=15, m[5];
pt1=&x;
pt2=pt1;
pt1 = m; // pt1 = &m[0]; m ' ,
// .
:
// P2_5.CPP
|
|
#include < iostream>
Using namespace std;
Int main ()
{
int x = 10;
int *px = &x;
cout << " x =" << x << endl;
cout << "*px =" << *px << endl;
x* = 2; // x = x*2;
cout << " * px =" << *px << endl;
*px += 2; // *px =*px + 2;
cout << " * px=, =" << x << endl;
Return 0;
}
:
x = 10
*px = 10
*px = 20
*px, x = 22
- ,
:
int *pt1, *pt2;
pt1 = (int*) &pt2; // pt1 ',
// pt2
, :
int y,*pt1, *pt2 =&y;
pt1 = (int*) & pt2;.
" & ":
( '), : vp = &345;
, : vp = & (x + y);.
:
;
;
;
.
, - :
// P2_6.CPP -
#include < iostream>
Using namespace std;
Void main (void)
{
int *ptr1 = (int*)100;
int *ptr2 = (int*) 200;
ptr1++;
ptr2 -= 10;
cout << "ptr1=" << ptr1 << endl;
cout << "ptr2=" << ptr2 << endl;
cout << "ptr2 - ptr1=" << ptr2 - ptr1 << endl;
}
:
ptr1 = 00000068
ptr2 = 000000A0
ptr2 - ptr1 = 14
ptr1++ 4 , int 4 , ptr2-=10 40 . .
2.4
++ ' . : int mas [20]; ' mas - () , &mas[0].
:
, , mas[2] mas[i];
, , *(mas +2) *(mas+i).
' -, :
int mas [20];
int *ptr1;
ptr1 = mas; // ptr1 = &mas[0];
ϳ int mas [20]; &mas[0] mas .
: int mas[10] = {0}; ' 0. , .
, float mas [10] ={ 12.2, 34.56 };, 0.
, .
:
< > < ' > [n] //
// n
< > < ' > [n] = { } //
< > < ' > [ ] = { } //
:
float m[6];
float m[6] = { 3.4, 4.5, 5.6, 6.7, 8.9, 10.3 };
float m[ ] = { 3.45, 4.56, 5.67, 6.78 };
, :
int mas [2][5] ={ 1, 2, 3, 4, 5,
10, 11, 13, 14, 25 };
int mas [2][5] ={ {1, 2, 3, 4, 5},
{10, 11, 13, 14, 25} };
int mas [ ][5] ={ 1, 2, 3, 4, 5,
10, 11, 13, 14, 25 };.
, .
. , .
' ', , mas[1] 1, p = &mas[0], p=p + 1 (p += 1) i p + i;. , , , :
|
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[] = x[0] + *sizeof ();.
1 2 , : ==,!=, <, <=, >, >=.
, 1 < 2 , 1 , 2. .
, , , . " " . , , :