Two-dimensional pointer malloc and free

Brush Leetcode 169, the first use of the two-dimensional pointer, dead and alive, but show ' double free or corruption out '

Change the two-dimensional pointer to a two-dimensional array and then look at the code carefully before you find the malloc error ....

Mark the memory allocation and release of the two-dimensional pointer.

int A[m][n]
int** A;
A = (int**) malloc (sizeof (int*) *m);
for (int i = 0; i < m; i++) {
     A[i] = (int*) malloc (sizeof (int) *n);
}

for (int i = 0; i < m; i++) {free
     (a[i]);
}
Free (a);