cpp3.cpp

languige算法的Ｃ语言程序实现

#include <iostream.h>

double Languige(double x0)
{
double Ln=0;
double l;
int n,i,j;

cout<<"请输入变量的个数:";
cin>>n;

double *x=new double[n];
double *f=new double[n];
    
for(i=0;i<n;i++)
{
  cout<<"请输入自变量x("<<i<<")的值:";
  cin>>x[i];
}

for(i=0;i<n;i++)
{
  cout<<"请输入因变量f("<<i<<")的值:";
  cin>>f[i];
}

for(i=0;i<4;i++)
{
  l=1;
        for(j=0;j<4;j++)
  {
   if(i!=j)
    l=l*(x0-x[j])/(x[i]-x[j]);
  }   
         Ln=Ln+f[i]*l;
}
return Ln;
}

void main()
{
   double x;
   cout<<"请输入被插值x:";
   cin>>x;
   cout<<"x="<<x<<"的函数值为:"<<Languige(x)<<endl;
}