收集的C语言算法程序

#include<iostream.h>//确定要计算的角度值#define N 0.57891void main(){       double x[4]={0.4,0.5,0.6,0.7};       double y[4]={0.38942,0.47943,0.56464,0.64422};       double xx=N,yy=0;       int i,k;       //套用拉格朗日插值多项式求解       for(k=0;k<=3;k++)       {              for(i=0;i<=3;i++)              {                     if(i!=k)                     {                            y[k]*=(xx-x[i])/(x[k]-x[i]);                     }              }              yy+=y[k];       }       //输出程序的运行结果       cout<<"经用三次插值法计算得知\n"<<"sin(0.57891)的近似值为：";       cout<<yy<<endl;}