Task 1: "Common Factors

You are given 2 positive numbers $M and $N.

Write a script to list all common factors of the given numbers.

Example 1:

Input:
    $M = 12
    $N = 18

Output:
    (1, 2, 3, 6)

Explanation:
    Factors of 12: 1, 2, 3, 4, 6
    Factors of 18: 1, 2, 3, 6, 9

Example 2:

Input:
    $M = 18
    $N = 23

Output:
    (1)

Explanation:
    Factors of 18: 1, 2, 3, 6, 9
    Factors of 23: 1


My notes: simple, find factors and then intersect.


Task 2: "Interleave String

You are given 3 strings; $A, $B and $C.

Write a script to check if $C is created by interleave $A and $B.

Print 1 if check is success otherwise 0.
Example 1:

Input:
    $A = "XY"
    $B = "X"
    $C = "XXY"

Output: 1

EXPLANATION

"X" (from $B) + "XY" (from $A) = $C

Example 2:

Input:
    $A = "XXY"
    $B = "XXZ"
    $C = "XXXXZY"

Output: 1

EXPLANATION

"XX" (from $A) + "XXZ" (from $B) + "Y" (from $A) = $C

Example 3:

Input:
    $A = "YX"
    $B = "X"
    $C = "XXY"

Output: 0

My notes: It's not quite clear what "interleaving" means here, but I'm
going to assume that it means "take a PREFIX of any length from one string,
followed by a PREFIX of any length from the other string, then continue
with the parts of the strings not yet consumed".  Relatively easy.