20用两个栈实现队列
作者:
什么意思O_o
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2024-11-11 16:35:53
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所有人可见
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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() {
return s1.empty();
}
};
/**
* 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();
*/