Min Stack

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 to store the running minimum alongside each value. Keep a second stack, or push pairs of (value, minSoFar). On push, the new min is min(x, current min). On pop, you drop both, so the previous minimum comes back automatically. The classic pitfall is the duplicate case from Example 2. If your min stack only pushes when x is strictly less than the current min, a single pop of one 2 wipes out the minimum for the other 2. Push on less-than-or-equal, or use the pair approach and skip the problem entirely. Second pitfall: parsing. Split each string on the space, and remember negative numbers like -2 parse fine as integers. Only collect output for pop, top, and getMin. With 10^5 operations, anything that scans the stack for the minimum will time out. If the parsing or duplicate logic jams during the live OA, StealthCoder is the hedge that gives you the working version.

If this hits your live OA and you blank, StealthCoder solves it in seconds, invisible to the proctor.