A more space-efficient implementation of stack with minimum

stackWIthMinImp2.go

type stackWithMin struct {
	data     []int
	minStack stack //utilizes the stack implementation we defined above!
}

func (s *stackWithMin) pop() int {
	popped := s.data[len(s.data)-1]
	s.data = s.data[:len(s.data)-1]
	if popped == s.min() { //if you've popped the min, move it off the minStack!
		s.minStack.pop()
	}
	return popped
}

func (s *stackWithMin) push(item int) {
	s.data = append(s.data, item)
	if item <= s.min() { //if the incoming item is less than the current min
		s.minStack.push(item)
	}
}

func (s *stackWithMin) min() int {
	if s.minStack.isEmpty() {
		return 100000000000000000 //really large number
	}
	return s.minStack.peek()
}