type MyQueue struct {
InputStack []int //輸入棧
OutputStack []int //輸出棧
}
/** Initialize your data structure here. */
func Constructor() MyQueue {
queue := MyQueue{[]int{}, []int{}}
return queue
}
/** Push element x to the back of queue. */
func (this *MyQueue) Push(x int) {
//元素加入輸入棧
this.InputStack = append(this.InputStack, x)
}
/** Removes the element from in front of queue and returns that element. */
func (this *MyQueue) Pop() int {
//當輸出棧不爲空的，那就直接取出輸出棧頂元素
if len(this.OutputStack) != 0 {
x := this.OutputStack[len(this.OutputStack)-1]
this.OutputStack = this.OutputStack[:len(this.OutputStack)-1]
return x
}
//如果輸出棧爲空，但是輸入棧不爲空，那就把輸入棧的元素放進輸出棧，並去除棧頂元素
if len(this.InputStack) != 0 {
for i := len(this.InputStack); i > 0; i-- {
this.OutputStack = append(this.OutputStack, this.InputStack[i-1])
this.InputStack = this.InputStack[:len(this.InputStack)-1]
}
x := this.OutputStack[len(this.OutputStack)-1]
this.OutputStack = this.OutputStack[:len(this.OutputStack)-1]
return x
}
return 0 //兩個棧都是空的
}
/** Get the front element. */
func (this *MyQueue) Peek() int {
//如果存在輸出棧元素 那就直接輸出棧頂元素
if len(this.OutputStack) != 0 {
return this.OutputStack[len(this.OutputStack)-1]
}
if len(this.InputStack) != 0 {
for i := len(this.InputStack); i > 0; i-- {
this.OutputStack = append(this.OutputStack, this.InputStack[i-1])
this.InputStack = this.InputStack[:len(this.InputStack)-1]
}
return this.OutputStack[len(this.OutputStack)-1]
}
return 0
}
/** Returns whether the queue is empty. */
func (this *MyQueue) Empty() bool {
if len(this.InputStack)+len(this.OutputStack) == 0 {
return true
}
return false
}
/**
* Your MyQueue object will be instantiated and called as such:
* obj := Constructor();
* obj.Push(x);
* param_2 := obj.Pop();
* param_3 := obj.Peek();
* param_4 := obj.Empty();
*/