33.cpp

追赶法解求解方程组

// 33.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include<iostream.h>
#include<math.h>
#include<stdlib.h>

//追赶法解三对角线方程组
void main()
{
   int N,i;
   cout<<" 输入主对角线维数N：\n";
   cin>>N;
   double *a= new double[N-1];
   double *b=new double[N];   
   double *c= new double[N-1];
   double *f= new double[N];   
   cout<<"input array a[]:\n";  
   for(i=0;i<N-1;i++) 
   cin>>a[i];
   cout<<"input array b[]:\n";
   for(i=0;i<N-1;i++) 
   cin>>b[i];
   cout<<"input array c[]:\n";
   for(i=0;i<N-1;i++)
   cin>>c[i];
   cout<<"input array f[]:\n";
   for(i=0;i<N;i++)
   cin>>f[i];

   for(i=0;i<N-1;i++)
	{
   c[i]=c[i]/b[i];
   b[i+1]=b[i+1]-a[i]*c[i];
   if(i==0) f[i]=f[i]/b[i];  
   else 
   f[i]=(f[i]-a[i-1]*f[i-1])/b[i];
   }
   f[N-1]=(f[N-1]-a[N-2]*f[N-2])/b[N-1];
   for(i=N-2;i>=0;i--)
   f[i]=f[i]-c[i]*f[i+1];
   for(i=0;i<N;i++)
   cout<<f[i]<<"　,";
   exit(0);
}