Min Stack

For this practice version, exercise the stack through the operation stream below.
Process operations on a stack that can return its current minimum in constant time.
push x pushes integer x and produces no output.
pop removes and returns the top value.
top returns the top value without removing it.
getMin returns the smallest value currently in the stack.
Return the outputs of every operation except push, in encounter order.

Function
processMinStack(operations: String[]) → int[]

Examples
Example 1
operations = ["push -2","push 0","push -3","getMin","pop","top","getMin"]
return = [-3,-3,0,-2]
The minimum becomes -3. Popping returns -3, exposing top 0 and minimum -2.
Example 2
operations = ["push 2","push 2","getMin","pop","getMin"]
return = [2,2,2]
Duplicate minima are tracked independently, so one pop leaves the same minimum.

Constraints
1 <= operations.length <= 10^5.
Pushed values are 32-bit signed integers.
Every pop, top, and getMin operation is issued on a nonempty stack.

The trick is a second stack that stores the minimum at each depth. On push x, append x to the main stack and append min(x, current min) to the min stack. On pop, remove from both. getMin just reads the top of the min stack. Every operation is O(1), and the total is O(n) over up to 10^5 operations. The pitfall is the single-variable minimum. Once you pop it, you've lost the previous one. Example 2 tests duplicates: push 2 twice, pop once, and the min must still be 2. Pushing the min on every push, not only when it changes, handles that for free. Watch parsing too. Split on a space and convert with a 32-bit safe integer parse, since negatives show up. Only pop, top, and getMin add to the output list. If your parsing or edge cases fall apart mid-OA, StealthCoder is the hedge that gets you unstuck.

The honest play: practice the pattern, and have StealthCoder ready for the one you didn't see coming.