Min Stack

Design a stack that supports push, pop, top, and retrieving the minimum element in constant time.

• push(x) -- Push element x onto stack.
• pop() -- Removes the element on top of the stack.
• top() -- Get the top element.
• getMin() -- Retrieve the minimum element in the stack.

设计一个堆支持push，pop，top和瞬间检索最小元素的功能。

学过数据结构就很简单了，而且c++专门有stack结构，代码如下：

class MinStack {private:       stack<int> content;      stack<int> mins;  public:    void push(int x) {          content.push(x);          if(mins.empty() || x <= mins.top())              mins.push(x);      }        void pop() {          int top = content.top();          content.pop();          if(top == mins.top())          {              mins.pop();          }      }        int top() {          return content.top();      }        int getMin() {          return mins.top();      }  };