1 class MyQueue {
2 public:
3 /** Initialize your data structure here. */
4 MyQueue() {
5
6 }
7 stack<int> a;
8 stack<int> b;
9 /** Push element x to the back of queue. */
10 void push(int x) {
11 a.push(x);
12 }
13
14 /** Removes the element from in front of queue and returns that element. */
15 int pop() {
16 int len=a.size();
17 for(int i=0;i<len;i++){
18 b.push(a.top());
19 a.pop();
20 }
21 int tmp=b.top();
22 b.pop();
23 for(int i=0;i<len-1;i++){
24 a.push(b.top());
25 b.pop();
26 }
27 return tmp;
28 }
29
30 /** Get the front element. */
31 int peek() {
32 int len=a.size();
33 for(int i=0;i<len;i++){
34 b.push(a.top());
35 a.pop();
36 }
37 int tmp=b.top();
38 for(int i=0;i<len;i++){
39 a.push(b.top());
40 b.pop();
41 }
42 return tmp;
43 }
44
45 /** Returns whether the queue is empty. */
46 bool empty() {
47 return a.empty();
48 }
49 };
50
51 /**
52 * Your MyQueue object will be instantiated and called as such:
53 * MyQueue* obj = new MyQueue();
54 * obj->push(x);
55 * int param_2 = obj->pop();
56 * int param_3 = obj->peek();
57 * bool param_4 = obj->empty();
58 */
