Hi
Im a newbie in C. But i know fortran very well. I try things i do in fortran in c. I'm trying to declare a 2 dimensional matrix globally without specific sizes. Later im planing to allocate it according to input. I can do this
float a[]; or this a[10] or this a[10][10]
But i cant do this
float a[][] or this a[2][] or this a[][3]
Im trying to do something like
real :: a(:,: ) (in fortran)
Can you show me how to declare and allocate according to input?
If you don't know the size until runtime, you do this
Code:double **array; int row, col; // initialise row/col somehow array = malloc( row * sizeof(*array); for ( r = 0 ; r < row ; r++ ) { array[r] = malloc( col * sizeof(*array[r]); } // do stuff // when you're done for ( r = 0 ; r < row ; r++ ) { free(array[r]); } free(array);
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
If at first you don't succeed, try writing your phone number on the exam paper.
the alternative that has a lot less complexity to it, and less management of pointers is to allocate a single block of data and compute the array index yourself.
Question 6.16
