ex10-02.cpp

数据结构常用算法合集

//EX10-02.cpp
#include <iostream.h>	//cout,cin
#include <conio.h>		// getch()
#include <iomanip.h>
#include <math.h>
const float PI=3.14159;
float xn(float,int);
float fn(int);
void main()
{ float sinx=0,x=PI/2,second_pi,percent;
  int n=1,count=0;
  second_pi=sin(PI/2);
  cout<<"No. sin(PI/2)  [Calcuate] [--Error--]\n";
  do
  {
    if (count%2==0)
    sinx=sinx+xn(x,n)/fn(n);
    else
    sinx=sinx-xn(x,n)/fn(n);
    n+=2;
    count++;
    percent = second_pi-sinx;
    cout << setw(3)<<count
         << setw(10)<<second_pi
         << setw(12)<<sinx
         << setw(12)<<percent<<endl;
  }
  while (fabs(percent)>=0.00001);
  getch();
}
float xn(float x,int n)
{ int i;
  float sum=1;
  for (i=0;i<n;i++)
  sum = sum * x;
//  cout <<"sum="<<sum<<endl;
  return sum;
}
float fn(int n)
{ float f=1;
  int i;
  for (i=1;i<=n;i++)
  f = f * i;
//  cout << "f="<<f<<endl;
  return f;
}