包含min函数的栈

 1 class Solution {
 2 private:
 3     stack<int> s;
 4     stack<int> assistant;
 5 public:
 6     void push(int value) {
 7         
 8             s.push(value);
 9         if(assistant.empty())
10             assistant.push(value);
11         else if(value>assistant.top())
12             assistant.push(assistant.top());
13             else
14             assistant.push(value);
15     }
16     void pop() {
17         s.pop();
18         assistant.pop();
19     }
20     int top() {
21         return s.top();
22     }
23     int min() {
24         return assistant.top();
25     }
26 };