Leetcode Note :Go - Implement Stack using Queues
Implement Stack using Queues - LeetCode
https://leetcode.com/problems/implement-stack-using-queues/
- Go 言語で取り組んだメモ
所感
- Stack を実装する
- ちょっと実践味というか、実際の実装感あってよい
回答
Implement Stack using Queues - LeetCode
https://leetcode.com/problems/implement-stack-using-queues/solution/
Golang 1 queue, pop O(n), push O(1) - LeetCode Discuss
https://leetcode.com/problems/implement-stack-using-queues/discuss/570763/Golang-1-queue-pop-O(n)-push-O(1)
type MyStack struct {
Queue MyQueue
}
func Constructor() MyStack {
return MyStack{
Queue: MyQueue{[]int{}},
}
}
func (this *MyStack) Push(x int) {
this.Queue.push(x)
}
func (this *MyStack) Pop() int {
for i := 0; i < this.Queue.size() - 1; i++ {
this.Queue.push(this.Queue.pop())
}
return this.Queue.pop()
}
func (this *MyStack) Top() int {
for i := 0; i < this.Queue.size() - 1; i++ {
this.Queue.push(this.Queue.pop())
}
x := this.Queue.pop()
this.Queue.push(x)
return x
}
func (this *MyStack) Empty() bool {
return this.Queue.empty()
}
type MyQueue struct {
Data []int
}
func (q *MyQueue) push(x int) {
q.Data = append(q.Data, x)
}
func (q *MyQueue) pop() int {
if len(q.Data) > 0 {
x := q.Data[0]
q.Data = q.Data[1:]
return x
}
return 0
}
func (q *MyQueue) size() int {
return len(q.Data)
}
func (q *MyQueue) empty() bool {
return len(q.Data) == 0
}
/**
* Your MyStack object will be instantiated and called as such:
* obj := Constructor();
* obj.Push(x);
* param_2 := obj.Pop();
* param_3 := obj.Top();
* param_4 := obj.Empty();
*/- MyQueue を定義して Stack を実装
- データはスライスで管理して push や pop は append 使えば良い