155. Min Stack

Posted 2020-11-07 高数考了59

 1 static int wing=[]()
 2 {
 3     std::ios::sync_with_stdio(false);
 4     cin.tie(NULL);
 5     return 0;
 6 }();
 7 
 8 class MinStack 
 9 {
10 private:
11     stack<int> s1;
12     stack<int> s2;
13     
14     public:
15     /** initialize your data structure here. */
16     
17     void push(int x) 
18     {
19         s1.push(x);
20         if(s2.empty()||x<=getMin())
21             s2.push(x);
22     }
23     
24     void pop() 
25     {
26         if(s1.top()==getMin())
27             s2.pop();
28         s1.pop();
29     }
30     
31     int top() 
32     {
33         return s1.top();
34     }
35     
36     int getMin() 
37     {
38         return s2.top();
39     }
40 };
41 
42 /**
43  * Your MinStack object will be instantiated and called as such:
44  * MinStack obj = new MinStack();
45  * obj.push(x);
46  * obj.pop();
47  * int param_3 = obj.top();
48  * int param_4 = obj.getMin();
49  */

这个最小栈和普通栈操作差不多，只是多了个getMin()函数用来获取栈内最小值。

为了完成获取最小值的函数，需要借助一个辅助栈来存放当前栈内最小值。