#include <stdio.h>

double det(double arr[][3])
{
	double ans;
	ans=(((arr[0][0]*arr[1][1]*arr[2][2])+
		(arr[0][1]*arr[1][2]*arr[2][0])+
		(arr[0][2]*arr[1][0]*arr[2][1]))-
		((arr[0][2]*arr[1][1]*arr[2][0])+
		(arr[0][0]*arr[1][2]*arr[2][1])+
		(arr[0][1]*arr[1][0]*arr[2][2])));
	return ans;
}

void sol(double x,double y,double z)
{
	printf("Solution:\n");
	printf("x = %g\n",x);
	printf("y = %g\n",y);	
	printf("z = %g\n",z);
}

void accept(double arr [][3],double arr1[3])
{
	int i,j;
	printf("\n\nAccepted equations:\n");
	for (i=0;i<3;i++)
		{
		j=0;
		if (arr[i][j]!=0 || arr[i][j+1]!=0 || arr[i][j+2]!=0)
			{
				for (j=0;j<3;j++)
					{
						switch (j)
						{
							case 0:
								if (arr[i][j]!=0)
									if (arr[i][j]==1)
										printf("x",arr[i][j]);
									else
										printf("%gx",arr[i][j]);
								break;
							case 1:
								if (arr[i][j]>0)
								{
									if ((arr[i][j-1]!=0) && (arr[i][j]==1))
										printf("+y",arr[i][j]);
									else if (arr[i][j-1]!=0) 
										printf("+%gy",arr[i][j]);
									   else
										printf("%gy",arr[i][j]);
								}
								else if (arr[i][j]<0)
									printf("%gy",arr[i][j]);
								break;
							case 2:
							if (arr[i][j]>0)
								{
									if (((arr[i][j-1]!=0) || (arr[i][j-2]!=0)) && (arr[i][j]==1))
										printf("+z",arr[i][j]);
									else if (arr[i][j-1]!=0) 
										printf("+%gz",arr[i][j]);
									   else
										printf("%gz",arr[i][j]);
								}
								else if (arr[i][j]<0)
									printf("%gz",arr[i][j]);
								break;
						}
					}
				}
				else
					printf("0");
		   printf("=%g\n",arr1[i]);
	}
}

void input(double A[3][3],double X[3])
{
		
		printf("Enter coefficients and constants:\n");
		fflush(stdin);
		scanf("{{%lf,%lf,%lf},{%lf,%lf,%lf},{%lf,%lf,%lf}}={%lf,%lf,%lf}", 
&A[0][0], &A[0][1], &A[0][2], 
&A[1][0], &A[1][1], &A[1][2], 
&A[2][0], &A[2][1], &A[2][2], 
&X[0], &X[1], &X[2]);

}


int main()
{
	double coef[3][3]={0};
	double temp[3][3]={0};
	double con[3]={0};
	double main_det=0,solX=0,solY=0,solZ=0;
	int i=0,j=0,choice=0;

	while (choice!=2)
	{
		printf("\nMain Menu\n---------\n");
		printf("(1)Solve 3x3 linear equations system\n");
		printf("(2)Quit\n");
		printf("Enter your choice:");
		fflush(stdin);
		scanf("%d", &choice);
		
		if (choice==1)
			{		
				input(coef,con);
				accept(coef,con);
				main_det=det(coef);	
				if (main_det==0)
					{
						printf("\nThe metrix doesn't have one solution\n");
					}
					else
					{
						for (i=0;i<3;i++)
							for (j=0;j<3;j++)
								temp[i][j]=coef[i][j];
						for (i=0;i<3;i++)
							temp[i][0]=con[i];
						solX=det(temp)/main_det;
						for (i=0;i<3;i++)
							{
								temp[i][1]=con[i];
								temp[i][0]=coef[i][0];
							}
						solY=det(temp)/main_det;
						for (i=0;i<3;i++)
							{
								temp[i][2]=con[i];
								temp[i][1]=coef[i][1];
							}
						solZ=det(temp)/main_det;
						sol(solX,solY,solZ);
						choice=0;	
					}
			}
		else if (choice==2)
			printf("bye bye...\n");
		else
			printf("\nIncorrect Choice\n\n");
	}
	return 0;
}