# include <math.h>
# include <stdio.h>

# define N 3
# define M 3

void npmul(double [],int  ,double [],int ,double [],int );
//多項式乘積的程
void xiangguan(double [],int ,double [],int ,double [],int );
//這是一個求褶積的程序,調用了npmul().


void main()
{
	double x[M]={1,-1,-0.5};
	double h[N]={1,0.5,-0.5};
	
  	
	double *yy=new double [M+N-1];
	xiangguan(x,M,h,N,yy,M+N-1);
	getchar();
	for( i=0;i<M+N-1;i++)
		printf(" yy[%d]=%f\n",i,yy[i]);
	printf("ok\n");
	delete [] yy;
   
    
}


	
void xiangguan(double x[],int m,double h[],int n,double y[],int mn)
//這是一個求相關的程序 mn=m+n-1
{
    double temp=0.0;
	for(int i=0;i<m/2;i++)
	{
		temp=x[i];
		x[i]=x[m-1-i];
		x[m-1-i]=temp;
	}
	npmul(x,m,h,n,y,mn);
}

void npmul(double p[],int m ,double q[],int n,double s[],int k)
      //多項式相乘的子程序，k=m+n-1.
{
   	int i,j;
    for (i=0; i<=k-1; i++)
		s[i]=0.0;
    for (i=0; i<=m-1; i++)
		for (j=0; j<=n-1; j++)
			s[i+j]=s[i+j]+p[i]*q[j];
    return;
}