Task 4: Complete the following function: function SEARCHSTACK(stack, item) end function This function will take a stack and a value (called item) as input parameters, and return FALSE if item is not stored in the stack, otherwise return the stack without the element storing item. [6 marks] To check whether a column contains all numbers from 1 to 4 in a puzzle vector, we will do the following: 1. Create a stack called numbers, which contains all numbers from 1 to 4 2. Initialise a variable k to be 1 3. For the element k in a column, store the number in that element to a variable called value and call SEARCH- STACK(numbers, value) 4. If the function returns FALSE, then we should return FALSE as a number appears twice or not at all in the stack 5. If the function returns the stack, increase the value of k by one and go to step 3 6. If after checking all elements in the column, SEARCHSTACK has not returned FALSE, we return TRUE In the next task you will need to complete a function that carries out this algorithm for column of the input puzzle