Program to solve simultaneous equation using by Gauss Seidal Method

#include<stdio.h>

#include<conio.h>

#include<math.h>

int main()

{

int n,i,j,k,maxit;

float a[10][10],e,big,sum,temp,x[10],relerr,prod=1,prod1=1;

//clrscr();

printf("enter the allowable error :");

scanf("%f",&e);

printf("\nenter the maximum number of iteration :");

scanf("%d",&maxit);

printf("\nenter the number of equations :");

scanf("%d",&n);

printf("\nenter the co-efficients of equations :\n");

for(i=1;i<=n;i++)

 for(j=1;j<=(n+1);j++)

  scanf("%f",&a[i][j]);

printf("\nentered co-efficient matrix is\n");

for(i=1;i<=n;i++)

{

 for(j=1;j<=(n+1);j++)

  printf("%.2f\t",a[i][j]);

 printf("\n");

}

for(i=1,j=n;i<=n;i++,j--)

{

  prod=prod*a[i][i];

  prod1=prod1*a[i][j];

}

if(fabs(prod) < fabs(prod1))

{

  printf("diagonal dominancy");

  getch();

  return(0);

}

else

for(i=1;i<+n;i++)

  x[i]=0;

//printline();

for(i=1;i<=n;i++)

  printf("X%d\t",i);

printf("\n");

//printline();

for(k=1;k<=maxit;k++)

{

  big=0;

  for(i=1;i<=n;i++)

  {

    sum=0;

    for(j=1;j<=n;j++)

    {

      if(i!=j)

                sum=sum+a[i][j]*x[j];

    }//end for j

    temp=(a[i][n+1]-sum)/a[i][i];

    relerr=fabs((x[i]-temp)/temp);

    if(relerr>big)

      big=relerr;

    x[i]=temp;

    printf("%.2f\t",x[i]);

  }//end for i

  printf("\n");

  if(big<=e)

  {

    printf("\nconverges to a solution in %dth iteration",k);

    printf("\nsolution vector is:\n");

    for(i=1;i<=n;i++)

      printf("x[%d]=%.2f\n",i,x[i]);

    getch();

    return(0);

  }

    }//end for k

  printf("dose not converge in %d iterations",maxit);

  getch();

}