gaussseidel.c

#include<stdio.h>
//#include<conio.h>
#include<math.h>
#define ESP 0.0001
#define X1(x2,x3) ((17 - 20*(x2) + 2*(x3))/20)
#define X2(x1,x3) ((-18 - 3*(x1) + (x3))/20)
#define X3(x1,x2) ((25 - 2*(x1) + 3*(x2))/20)


void main()
{
  double x1=0,x2=0,x3=0,y1,y2,y3;
  int i=0;
  //clrscr();
 // printf("\n__________________________________________\n");
  printf("\n   x1\t\t   x2\t\t   x3\n");
  //printf("\n__________________________________________\n");
  printf("\n%f\t%f\t%f",x1,x2,x3);
  do
  {
   y1=X1(x2,x3);
   y2=X2(y1,x3);
   y3=X3(y1,y2);
   if(fabs(y1-x1)<ESP && fabs(y2-x2)<ESP && fabs(y3-x3)<ESP )
   {
     printf("\n__________________________________________\n");
     printf("\n\nx1 = %.3lf",y1);
     printf("\n\nx2 = %.3lf",y2);
     printf("\n\nx3 = %.3lf",y3);
     i = 1;
   }
   else
   {
     x1 = y1;
     x2 = y2;
     x3 = y3;
     printf("\n%f\t%f\t%f",x1,x2,x3);
   }
  }while(i != 1);

}