剑指 30. 包含min函数的栈

剑指 Offer 30. 包含min函数的栈

和力扣155. 最小栈一致

type MinStack struct {
    stack []int            //存储栈
    min []int            //辅助储存栈，存储最小值
}
/** initialize your data structure here. */
func Constructor() MinStack {
    return MinStack{
        stack: []int{},
        min: []int{},
    }
}
func (this *MinStack) Push(x int)  {
    this.stack = append(this.stack, x)
    if len(this.min) == 0 || x <= this.min[len(this.min)-1] { // 没有元素或者x小于最小值的时候，append到min最后
        this.min = append(this.min, x)
    }else {
        this.min = append(this.min, this.min[len(this.min)-1]) // 否则继续将上一个最小值append到min
    }
}
func (this *MinStack) Pop()  {
    this.stack = this.stack[:len(this.stack)-1]
    this.min = this.min[:len(this.min)-1]
}
func (this *MinStack) Top() int {
    if len(this.stack) == 0 {
        return 0
    }
    return this.stack[len(this.stack)-1]
}
func (this *MinStack) Min() int {
    if len(this.min) > 0 {
        return this.min[len(this.min)-1]
    }
    return 0
}