Write a C function that generates all the possible combinations of a set of items of a given size. It should have the following signature:

int** get_combs(int* items, int k, int len).

items: an array containing the given numbers

k: length of each combination

len: amount of numbers in items

This function should generate all possible combinations of items taken k at a time and return a 2-D array where each row contains one combination.

1. The combinations should be added to the 2-D array in their natural order

2. This 2-D array should be dynamically allocated in get_combs.

3. You will probably need to develop a helper function that actually computes the combinations.

4. Write the helper function recursively.

Use this code snippet (num_combs) to allocate space for the array:

int max(int a, int b){ return a > b ? a : b; }

int min(int a, int b){ return a < b ? a : b; }

int num_combs(int n, int k){ int combs = 1; int i;

for(i = n; i > max(k, n-k); i--){ combs *= i; }

for(i = 2; i <= min(k, n - k); i++){ combs /= i; } return combs;

}

The 2-D array will be used to print out the combinations.

Example :

How many items do you have: 5

Enter your items: 1 2 3 4 5

Enter k: 3

1 2 3

1 2 4

1 2 5

1 3 4

1 3 5

1 4 5

2 3 4

2 3 5

2 4 5

3 4 5