=== Main ===
Open file
initialize counter p
Read full string into a char array. BEEG array
Loop - for i = 0, i + 3 < array length, i++
    feed rolling 4-char snapshot into check function index range i to i+3
    if check true (no duplicates)
        print p to screen
    if check false (has duplicates)
        increment p
End Loop

=== Check function === Reads char array
Outer Loop - for i = 0, i < array length - 1, i++
    Inner Loop - for j = i+1, j < array length, j++
        if array[i] == array[j]
            return false
    End Inner Loop
End Outer Loop
return true

For Part B, change i+4 in lines 11 and 12 to i+14 (or size of range needed)