Gaussian elimination using C

I want to find the determinant of a square matrix of size 3x3 for this I am using Gaussian elimination so that I can multiply diagonal elements and get the determinant. The code used is given. It is converting the matrix into upper triangular but not giving the solution pls give me a solution.

    #include<stdio.h>
    void determinant (float A[3][3]);
    void main()
    { 
      int i,j;
      float A[3][3]={1,2,3,0,1,1,4,1,2};
      determinant(A);
      for(i=0;i<3;i++)
      {
         for(j=0;j<3;j++)
         { 
           printf("%ft",A[i][j]);
         }
         printf("n");
      }
    }

    void determinant (float A[3][3])
     {
      int i,j,k;
      for(k=0;k<2;k++)
      {
         for(i=k+1;i<3;i++)
        {
         for(j=0;j<3;j++)
          {
            A[i][j]=A[i][j]-(A[k][j]*(A[i][k]/A[k][k];
           }
         }
      }
    }