C++ Tutorial/Development/Math

Материал из C\C++ эксперт
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Create Random number

<source lang="cpp">#include <iostream>

  1. include <cstdlib>

using namespace std;

int main() {

 int magic;  
 int guess;  

 magic = rand(); // get a random number 
  
 cout << "Enter your guess: "; 
 cin >> guess; 

 if(guess == magic) 
    cout << "Right"; 

 return 0; 

}</source>

Enter your guess: 2

math library functions: log10, fabs, ceil, floor

<source lang="cpp">#include <iostream> using std::cout; using std::endl; using std::fixed;

  1. include <iomanip>

using std::setprecision;

  1. include <cmath>

using namespace std; int main() {

  cout << fixed << setprecision( 1 ); 
  cout << "\nlog10(" << 1.0 << ") = " << log10( 1.0 )<< "\nlog10(" << 10.0 <<) = " << log10( 10.0 ) 
     << "\nlog10(" << 100.0 << ") = " << log10( 100.0 ) ;
  cout << "\nfabs(" << 13.5 << ") = " << fabs( 13.5 )<< "\nfabs(" << 0.0 << ") = " << fabs( 0.0 )
     << "\nfabs(" << -13.5 << ") = " << fabs( -13.5 );
  cout << "\nceil(" << 9.2 << ") = " << ceil( 9.2 )<< "\nceil(" << -9.8 << ")= " << ceil( -9.8 );
  cout << "\nfloor(" << 9.2 << ") = " << floor( 9.2 )<< "\nfloor(" << -9.8 <<) = " << floor( -9.8 );
  return 0;

}</source>

log10(1.0) = 0.0
log10(10.0) = 1.0
log10(100.0) = 2.0
fabs(13.5) = 13.5
fabs(0.0) = 0.0
fabs(-13.5) = 13.5
ceil(9.2) = 10.0
ceil(-9.8) = -9.0
floor(9.2) = 9.0
floor(-9.8) = -10.0

math library functions: pow, fmod, sin, cos, tan

<source lang="cpp">#include <iostream> using std::cout; using std::endl; using std::fixed;

  1. include <iomanip>

using std::setprecision;

  1. include <cmath>

using namespace std; int main() {

  cout << fixed << setprecision( 1 ); 
  cout << "\npow(" << 2.0 << ", " << 7.0 << ") = " << pow( 2.0, 7.0 ) << "\npow(" << 9.0 << ", " 
     << 0.5 << ") = " << pow( 9.0, 0.5 );
  cout << setprecision(3) << "\nfmod("<< 13.675 << ", " << 2.333 << ") = "           << fmod( 13.675, 2.333 ) << setprecision( 1 ); 
  cout << "\nsin(" << 0.0 << ") = " << sin( 0.0 ); 
  cout << "\ncos(" << 0.0 << ") = " << cos( 0.0 );
  cout << "\ntan(" << 0.0 << ") = " << tan( 0.0 ) << endl;
  return 0;

}</source>

pow(2.0, 7.0) = 128.0
pow(9.0, 0.5) = 3.0
fmod(13.675, 2.333) = 2.010
sin(0.0) = 0.0
cos(0.0) = 1.0
tan(0.0) = 0.0

Raise x to the y power

<source lang="cpp">#include <iostream> using std::cout; using std::cin; using std::endl; int main() {

  int base;  
  int exponent; 
  int i; 
  int power; 
  i = 1; 
  power = 1;
  cout << "Enter base as an integer: ";  
  cin >> base;
  cout << "Enter exponent as an integer: "; 
  cin >> exponent;
  while ( i <= exponent ) 
  {
     power *= base;
     i++;
  } 
  cout << power << endl; 
  return 0; 

}</source>

Enter base as an integer: Joe
Enter exponent as an integer: 64

Use math function: cos, sin, tan

<source lang="cpp">#include <cmath>

  1. include <iostream>

using namespace std; int main() {

 double angle, dsine,dcos,dtan;
 cout << "Please enter an angle in radians \n";
 cin >> angle;
 dcos =cos(angle);
 dsine =sin(angle);
 dtan =tan(angle);
 cout << " Your angles trigonometric functions are \n";
 cout << " Sine is " << dsine << "\n";
 cout << " Cosine is " << dcos << "\n";
 cout << " Tangent is " << dtan << "\n";
 return 0;

}</source>

Please enter an angle in radians
12
 Your angles trigonometric functions are
 Sine is -0.536573
 Cosine is 0.843854
 Tangent is -0.63586

Use math function: sqrt, pow, log

<source lang="cpp">#include <cmath>

  1. include <iostream>

using namespace std; int main() {

 double number, dsqrt,dpow,dlog;
 cout << "Please enter a number \n";
 cin >> number;
 dsqrt =sqrt(number);
 dpow =pow(number,5);
 dlog =log(number);
 cout << " Math Example\n";
 cout << " Square Root is " << dsqrt << "\n";
 cout << " Raised to the fifth power is " << dpow << "\n";
 cout << " Log is " << dlog << "\n";
 return 0;

}</source>

Please enter a number
12
 Math Example
 Square Root is 3.4641
 Raised to the fifth power is 248832
 Log is 2.48491

Use the abs() function

<source lang="cpp">#include <iostream>

  1. include <cstdlib>

using namespace std;

int main() {

 int result; 

 result = abs(-10); 

 cout << result; 

 return 0; 

}</source>

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