AcWing 20. 用两个栈实现队列
原题链接
简单
作者:
小bei
,
2024-02-12 21:24:38
,
所有人可见
,
阅读 33
class MyQueue {
public:
/** Initialize your data structure here. */
stack<int> s1,s2;
MyQueue() {
}
/** Push element x to the back of queue. */
void push(int x) {
s1.push(x);
}
/** Removes the element from in front of queue and returns that element. */
int pop() {
while(s1.size()>1){
s2.push(s1.top());
s1.pop();
}
int t=s1.top();
s1.pop();
while(s2.size()){
s1.push(s2.top());
s2.pop();
}
return t;
}
/** Get the front element. */
int peek() {
while(s1.size()>1){
s2.push(s1.top());
s1.pop();
}
int t=s1.top();
while(s2.size()){
s1.push(s2.top());
s2.pop();
}
return t;
}
/** Returns whether the queue is empty. */
bool empty() {
if(s1.size()) return false;
else return true;
}
};
/**
* Your MyQueue object will be instantiated and called as such:
* MyQueue obj = MyQueue();
* obj.push(x);
* int param_2 = obj.pop();
* int param_3 = obj.peek();
* bool param_4 = obj.empty();
*/