#include "cbox2.h"/*[function Solve :Solution of the linear systems of equations by the Gauss elimination method providing for interchanging rows when encountering a zero diagonal coeficient.A : Syestem MatrixB:  Originally it contains the Independent coefficients.  After solutions it	contains the values of the syestem unknowns.                            				   				N:  Actual number of unknowns.Dim: Row and Column Dimension of A. ]*/void Solve(A,B,D,N,Dim)	float A[81][81],B[81],*D;  /*[ D is assigned some value here ]*/  	int N,Dim;{	int N1,i,j,k,i1,l,k1,found;	float c;	/*[ found is a flag which is used to check if any non zero coeff is found ]*/				N1 = N - 1;	for(k=1;k<=N1;k++)	{		k1 = k + 1;		c = A[k][k];				if( (fabs(c) - tol) <=0 )		{			found = 0;			for(j=k1;j<=N;j++)  /*[Interchange rows to get Nonzero ]*/		        {            	if( (fabs(A[j][k]) - tol) <=0.0 )                 {				 	for(l=k;l<=N;l++)                    {                     	c = A[k][l];                        A[k][l] = A[j][l];                        A[j][l] = c;                     }				  		c = B[k];				  		B[k] = B[j];				  		B[j] = c;				  		c = A[k][k];						found = 1;		/*[ coeff is found ]*/						break;				}			}		 }		if(!found)		{			printf("Singularity in Row %d 1",k);	   		(*D) = 0.0;          	    	return;   /*[ If no coeff is found the control is transferred to main ]*/		}		/*[ Divide row by diagonal coefficient ]*/		  		c = A[k][k];		for(j = k1;j<=N;j++)		   A[k][j] /= c;		B[k] /= c;   /*[ Eliminate unknown X[k] from row i ]*/		for(i = k1;i<=N; i++)		{		  c = A[i][k];		  for(j = k1;j<= N;j++)		 	A[i][j] -= c*A[k][j];		  B[i] -= c*B[k];		}	}/*[ Compute the last unknown ]*/	if((fabs(A[N][N]) - tol) > 0.0)	{	   B[N] /= A[N][N];/*[Apply back substitution to compute the remaining unknowns  ]*/	   for(l = 1;l<= N1;l++)	   {	      k = N - l;	      k1 = k +1;	      for(j = k1;j<=N;j++)			B[k] -= A[k][j]*B[j];	   }/*[Compute the value of the determinent ]*/	(*D) = 1.0;	for(i=1;i<=N;i++)	  (*D) *= A[i][i];   }  else  {  		printf("Singularity in Row %d 2",k);	   	(*D) = 0.0;   }            return;	}