拉格朗日插值

#include <iostream>
using namespace std;

double laglang(double t,double *x,double *y)
{
    double r=0.0;
    double temp=1.0;
    for (int k=0;k<5;k++)
    {
        temp=1.0;
        for (int j=0;j<5;j++)
        {
            if (j!=k)
            {
                temp*=(t-x[j])/(x[k]-x[j]);
            }
        }
        r+=temp*y[k];
    }
    return r;
}



int main()
{
    double T[5]={20.5,32.7,51.0,73.0,95.7};
    double R[5]={765.0,826.0,873.0,942.0,1032.0};
    double ans=0;
    ans=laglang(60.0,T,R);
    cout<<ans<<endl;
    system("pause");
}