Arrays: Dynamic memory allocation and deallocation for multi-dimensional arrays.

Example 1:

(a) Write a function double** alloc_lt_mat(int n) that dynamically allocates memory for a lower triangular matrix of n rows where the k-th row has only the first k columns.

(b) Write another function void dealloc_lt_mat(double** a, int n) that deallocates memory for a lower triangular matrix a[i][j] of n rows where k-th row has only the first k columns.

For example, the following code should run:

void main() {

double** a;

a = alloc_lt_mat(10);

a[5][3] = 9;

cout << aa[5][3] <

dealloc_lt_mat(a,10);

}