www.pudn.com > s.zip > s.cpp, change:2003-03-16,size:1676b

#include 
 
  
void main() 
{ 
	int i; 
	long double b[21],x[21],f[21],l,m[21],s[81],d[21],a[20],c[20]; 
	for(i=0;i<21;i++){ 
		x[i]=-4.0+i*0.4; 
		f[i]=1.0/(x[i]*x[i]*x[i]*x[i]+1.0); 
	} 
	for(i=0;i<20;i++){ 
		a[i]=1.0; 
		c[i]=1.0; 
	} 
	d[0]=2.0; 
	d[20]=2.0; 
	for(i=1;i<20;i++){ 
		d[i]=4.0; 
	} 
	b[0]=15.0*((f[1]-f[0])*5.0/2.0-256.0/(257.0*257.0)); 
	b[20]=15.0*(-256.0/(257.0*257.0)-(f[20]-f[19])*5.0/2.0); 
	for(i=1;i<20;i++){ 
		b[i]=75.0/2.0*(f[i+1]-2.0*f[i]+f[i-1]); 
	} 
	for(i=0;i<20;i++){ 
		l=a[i]/d[i]; 
		d[i+1]=d[i+1]-l*c[i]; 
		b[i+1]=b[i+1]-l*b[i]; 
	} 
	m[20]=b[20]/d[20]; 
	for(i=19;i>=0;i--){ 
		m[i]=(b[i]-c[i]*m[i+1])/d[i]; 
	} 
	for(i=0;i<20;i++){ 
		s[4*i]=m[i]*5.0/12.0*(x[i+1]-x[i])*(x[i+1]-x[i])*(x[i+1]-x[i])+(f[i]*5.0/2.0-m[i]/15.0)*(x[i+1]-x[i]); 
		s[4*i+1]=m[i]*5.0/12.0*(x[i+1]-x[i]-0.1)*(x[i+1]-x[i]-0.1)*(x[i+1]-x[i]-0.1)+m[i+1]*5.0/12.0*(x[i]+0.1-x[i])*(x[i+1]-x[i]+0.1)*(x[i+1]-x[i]+0.1)+(f[i+1]*5.0/2.0-m[i+1]/15.0)*0.1+(f[i]*5.0/2.0-m[i]/15.0)*(x[i+1]-x[i]-0.1); 
		s[4*i+2]=m[i]*5.0/12.0*(x[i+1]-x[i]-0.2)*(x[i+1]-x[i]-0.2)*(x[i+1]-x[i]-0.2)+m[i+1]*5.0/12.0*(x[i]+0.2-x[i])*(x[i+1]-x[i]+0.2)*(x[i+1]-x[i]+0.2)+(f[i+1]*5.0/2.0-m[i+1]/15.0)*0.2+(f[i]*5.0/2.0-m[i]/15.0)*(x[i+1]-x[i]-0.2); 
		s[4*i+3]=m[i]*5.0/12.0*(x[i+1]-x[i]-0.3)*(x[i+1]-x[i]-0.3)*(x[i+1]-x[i]-0.3)+m[i+1]*5.0/12.0*(x[i]+0.3-x[i])*(x[i+1]-x[i]+0.3)*(x[i+1]-x[i]+0.3)+(f[i+1]*5.0/2.0-m[i+1]/15.0)*0.3+(f[i]*5.0/2.0-m[i]/15.0)*(x[i+1]-x[i]-0.3); 
	} 
	s[80]=m[20]*5.0/12.0*(x[20]-x[19])*(x[20]-x[19])*(x[20]-x[19])+(f[20]*5.0/2.0-m[20]/15.0)*(x[20]-x[19]); 
	l=-4.0; 
	for(i=0;i<81;i++){ 
		cout<