Delete middle element of a stack

Algorithm

1. Delete function.

   • if k is 1 then delete top element.
   • else store the top element in a temp variable.
   • Reduce size of input for recursion.
   • Call the function again with reduced input.
   • Put the temp variable back on the stack.

2. midDelete function.(main)

   • Base condition - If stack is empty, return.
   • Get the middle element
   • Delete the middle element.

Code

void del(stack<int> &s, int k)
{
    if (k == 1)
    {
        s.pop();
        return;
    }

    int temp = s.top();
    s.pop();

    del(s, k - 1);
    s.push(temp);
}

void midDelete(stack<int> s, int n)
{
    if (s.empty())
        return;

    int k = (n / 2) + 1;
    del(s, k);
}

References

• GFG: Delete middle element of a stack
• YouTube: