#include <stdio.h>
#include <stdlib.h>

int det(int);
int minor(int);
int main()
{
  int mat[10][10],dim,a,b;
  
  printf("Please enter an integer for matrix dimensions(1-10):");
  scanf("%d",&dim);
  for (a=0;a<=dim-1;a++)
  {
      for (b=0;b<=dim-1;b++)
      {
      mat[a][b]=rand()%10+1;
      printf(" %d",mat[a][b]);
      
                
      }
      printf("\n\n");
  }    
  
  
  
printf("Determinant for the matrix is: %d",det(mat));
  return 0;
}



int det(int mat[10][10])
{

int a,b,temp,length;
length=0;
for (a=0;a<10;a++)
{
if mat[a][0]!=0 length++;

}




if (mat[1][1]==0)
{
temp=mat[0][0];
return temp;
}

a=rand()%10;
b=rand()%10;

return ((-1)^(a+b))*mat[a][b]*det(minor(mat,a,b));


}

int minor(int mat[10][10], int x, int y)

{
int a,k,i,length,minor[10][10];


length=0;
for (a=0;a<10;a++)
{
if mat[a][0]!=0 length++;
}



for (i=0;i<length;i++)
{
	for (k=0;k<length;k++)
	{
		if (i<x && k<y)
	    		minor[i][k]=mat[i][k];
	    	else if (i>=x && k<y) 
	    		minor[i][k]=mat[i+1][k];
	    	else if (i<x && k>=y)
	    		minor[i][k]=mat[i][k+1];
	    	else if (i>=x && k>=y)
	    		minor[i][k]=mat[i+1][k+1];
	}
}
return minor;
}

This is a homework about calculating determinant of a matrix recursively, i don't think it is finished now so i know that there are some errors. But my problem is i cannot use mat[][] matrix while i try to calculate the length of the matrix. I know that i have a problem with passing the matrix to det but i can't figure it out.
Thanks for any help

Recommended Answers

All 4 Replies

> int det(int);
Fix this so it looks like your definition of the function.

> int a,k,i,length,minor[10][10];
Pick a different name - it's the same as your function.

thank you for the minor issue but i cannot see the problem with the prototype of det funcktion

> int det(int mat[10][10])
Does this look like just 'int' to you?

It's simple copy/paste int det(int mat[10][10]);

i didn't know that we have to declare the matrix inside the prototype, and i noticed that it is not just int :D

thank you

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