AcWing 20. 用两个栈实现队列

本题链接：AcWing 20. 用两个栈实现队列

本博客给出本题截图：

AC代码

代码：

class MyQueue {
public:
    /** Initialize your data structure here. */
    stack<int> stk, cache;
    MyQueue() {

    }

    /** Push element x to the back of queue. */
    void push(int x) {
        stk.push(x);
    }

    void copy(stack<int> &a, stack<int> &b) {
        while (a.size()) {
            b.push(a.top());
            a.pop();
        }
    }

    /** Removes the element from in front of queue and returns that element. */
    int pop() {
        copy(stk, cache);
        int res = cache.top();
        cache.pop();
        copy(cache, stk);
        return res;
    }

    /** Get the front element. */
    int peek() {
        copy(stk, cache);
        int res = cache.top();
        copy(cache, stk);
        return res;
    }

    /** Returns whether the queue is empty. */
    bool empty() {
        return stk.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();
 */

  

 

  
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文章来源: chen-ac.blog.csdn.net，作者：辰chen，版权归原作者所有，如需转载，请联系作者。

原文链接：chen-ac.blog.csdn.net/article/details/120926457