jiandan.cpp

计算方法的几个经典算法

#include<math.h>
#include<stdio.h>
main()
{
 int i,j,n;
 float x1[100],x2[100],a[100][100],b[100],ep,max;
 printf("input n :");
 scanf("%d",&n);
 printf("input B :\n");
 for(i=1;i<=n;i++)
    for(j=1;j<=n;j++)
       scanf("%f",&a[i][j]);
 printf("input F:");
 for(i=1;i<=n;i++)
    scanf("%f",&b[i]);
 for(i=1;i<=n;i++)
    x1[i]=0;
 for(i=1;i<=n;i++)
    {
     x2[i]=b[i];
     for(j=1;j<=n;j++)
	if(j!=i)x2[i]=x2[i]+a[i][j]*x1[j];}
 max=0;
 for(i=1;i<=n;i++)
    if(fabs(x2[i]-x1[i])>max)max=fabs(x2[i]-x1[i]);
printf("input ep :");
scanf("%f",&ep);
while(max>ep)
{for(i=1;i<=n;i++)
    x1[i]=x2[i];
 for(i=1;i<=n;i++)
    {
     x2[i]=b[i];
     for(j=1;j<=n;j++)
	if(j!=i)x2[i]=x2[i]+a[i][j]*x1[j];}
max=0;
for(i=1;i<=n;i++)
   if(fabs(x2[i]-x1[i])>max)
     max=fabs(x2[i]-x1[i]);
     }
printf("the result is :");
for(i=1;i<=n;i++)
   printf("x[%d]=%.5f  ",i,x2[i]);
printf("\n");
 }