stack and queue

 

I am doing revision for my exams and I came across this question which I need to find the contents of Q1 after the following code are executed.

The datas 

5, 7, 12, 4, 0, 4, 6, 8, 67, 34, 23, 5, 0, 44, 33, 22, 6, 0

The pusedo-code 

Q1=createQueue
S1=createStack
loop (not end of file)
    read number 
    if (number not 0)
        pushStack (S1,number)
    else
        popStack (S1,x)
        popStack (S1,x)
        loop (not empty S1)
            popStack (S1,x)
            enqueue (Q1,x)
        end loop
    end if
end loop

Here is my solutions

  • if number is not 0, push the numbers to the stack so now the stack becomes 

    6
22
33
44 
5
23
34
67
8
6
4
4
12
7
5

  • else pop the first 2 elements of the stack so now the stack becomes 

    33
44 
5
23
34
67
8
6
4
4
12
7
5

    • 3.loop stack !empty, pop the stack and enqueue in Q1.so now the stack is empty and the queue becomes 

    5,7,12,4,4,6,8,67,34,23,5,44,33

    33 is the first in the queue and 5 is the last of the queue.

    I double checked with the answer provided and found out that my answers is different

    The provided answer 

    7,5,34,67,8,6,4,33,44

    I am not sure who is correct. please help.

    You reasoning is in the correct direction, but there are three zeros in the input and you only seem to do the else logic for the last one. Keep in mind that the else clause is within the loop too. Try processing the input until each of them one by one.

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