package q155

type stackElem struct {
	val, min int
}

type MinStack struct {
	stack []stackElem
}

func Constructor() MinStack {
	return MinStack{}
}

func (s *MinStack) Push(val int) {
	minVal := val
	if len(s.stack) > 0 {
		minVal = min(minVal, s.GetMin())
	}
	s.stack = append(s.stack, stackElem{
		val: val, min: minVal,
	})
}

func (s *MinStack) Pop() {
	s.stack = s.stack[:len(s.stack)-1]
}

func (s *MinStack) Top() int {
	return s.stack[len(s.stack)-1].val
}

func (s *MinStack) GetMin() int {
	return s.stack[len(s.stack)-1].min
}

/**
 * Your MinStack object will be instantiated and called as such:
 * obj := Constructor();
 * obj.Push(val);
 * obj.Pop();
 * param_3 := obj.Top();
 * param_4 := obj.GetMin();
 */