#include<iostream.h>
#include<math.h>
#define pi acos(-1.)
double f(double x)
{
 double y;
 y=3*x+sin(x)-exp(x);
 return y;
}

double SubstenseTru(double a,double b,double e)       //弦截法
{

 for(double m=0.0;m-0.3604217>pow(10,-e)||0.3604217-m>pow(10,-e);1)
 {
  m=a-f(a)*(b-a)/(f(b)-f(a));
  cout<<m<<endl;
  if(f(a)*f(m)<0)
   b=m;
  else
   a=m;
 }
 return m;
}

double Dichotomy(double a,double b,double e)       //二分法
{

 for(double m=0;m-0.3604217>pow(10,-e)||0.3604217-m>pow(10,-e);1)
 {
  m=(a+b)*0.5;
  cout<<m<<endl;
  if(f(a)*f(m)<0)
   b=m;
  else
   a=m;

 }
 return m;
}

int main()
{
 double a,b,e;
 cout<<"Please input range from a to b,and the precision e: ";
 cin>>a>>b>>e;
    cout<<"二分法迭代过程为："<<endl;
 Dichotomy(a,b,e);
 cout<<"弦截法迭代过程为："<<endl;
 SubstenseTru(a,b,e);

 return 0;
}