5
0
1
0
-1
-1
right answer:
1
1

what is test 3?

who can give a tip

Instead of copying actually data, we might put a marked-number (index to copy) in the array.
For example,

            if (x > 0)
            {
                stack[q ++] = x;
            }
            else
            if (x == -1)
            {
                int y = stack[q - 1];
                if (y > 0)
                {
                    System.out.println(y);
                    q--;
                }
                else
                {
                    y = -y;
                    System.out.println(stack[y]);
                    stack[q - 1] = -(y - 1);
                    if (y == 0)
                    {
                        q--;
                    }
                }
            }
            else
            {
                stack[q] = -(q - 1); // negative numbers mean a copy.
                q ++;
            }

of course, this doesn't work for multiple continuous copy (e.g. 0, 0, 0 ..).

what is test 23?

Any hint for solving this problem?

8  -> 8
3  -> 8 3
4  -> 8 3 4
0  -> 8 3 4 8 3 4
-1 -> 8 3 4 8 3    output 4
-1 -> 8 3 4 8      output 3
-1 -> 8 3 4        output 8
-1 -> 8 3          output 4
1  -> 8 3 1

why the answer is
4 3 4 3?

Give solution plz! TLE 42

is that task in dynamic programming style?

is this because I am using java ?? Java is slower compared to c or c++. This program is normal stack operation isn't it? or some other algo is to be followed??

Test 4: crash (integer division by zero)
int main()
{
    int n;
    scanf("%d",&n);
    if (n>1000000 || n<1)
        return 1/(n-n);
    return 0;
}