deleting pointer array of pointer array

my program tends to crash when i try to delete this array...heres the basic setup

EDIT: my program SOMETIMES crashes..it crashes sometimes..and sometimes it runs smoothly

very weird stuff!
what is wrong?

Code:

---

int ** f;

int solve( int n, int capacity)
{
//create array
const int rows = n;
const int cols = capacity;


f = new int*[rows];
for(int i = 0; i < rows; i++)
    f[i] = new int[cols];

for(int j = 0; j < cols; j++)
    for(int i = 0; i < rows; i++)
        f[i][j] = 0;

//MORE CODE HERE

//time to delete array of array

for (int i = 0; i < rows; i++)
{
  delete [] f[i];  //CRASHES
  //f[i] = null;
}
delete [] f;
//f = null;
}

---

any ideas?

The problem probably lies in the code that you did not show, or even in other code, since f is a global variable.

I suggest that you avoid global variables and use a std::vector<int> or std::vector<std::vector<int> > instead.

Somewhere, your program is probably experiencing a buffer overflow that's overwriting your f array.
You need to go over it... carefully. These can be a real pain sometimes (usually only if you poorly wrote something, though).

Buffer overflows are easy to catch with a proper debugger. No need to painfully crawl through it by hand to see if you can spot anything.
Regardless, you should post the smallest compilable example that demonstrates the problem. That should get you help a little faster.