C++ Tutorial/Development/Math

Материал из C\C++ эксперт
Версия от 10:28, 25 мая 2010; Admin (обсуждение | вклад) (1 версия: Импорт контента...)
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Create Random number

#include <iostream> 
#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; 
}
Enter your guess: 2

math library functions: log10, fabs, ceil, floor

#include <iostream>
using std::cout;
using std::endl;
using std::fixed;
#include <iomanip>
using std::setprecision;
#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;
}
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

#include <iostream>
using std::cout;
using std::endl;
using std::fixed;
#include <iomanip>
using std::setprecision;
#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;
}
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

#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; 
}
Enter base as an integer: Joe
Enter exponent as an integer: 64

Use math function: cos, sin, tan

#include <cmath>
#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;
}
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

#include <cmath>
#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;
}
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

#include <iostream> 
#include <cstdlib>  
using namespace std; 
 
int main() 
{ 
  int result; 
 
  result = abs(-10); 
 
  cout << result; 
 
  return 0; 
}
10"