[LeetCode]Min Stack

 1 class MinStack {
 2 public:
 3     void push(int x) {
 4         elems.push(x);
 5         if (minElems.empty() || minElems.top() >= x) {
 6             minElems.push(x);
 7         }
 8     }
 9 
10     void pop() {
11         if (elems.top() == minElems.top()) {
12             minElems.pop();
13         }
14         elems.pop();
15     }
16 
17     int top() {
18         return elems.top();
19     }
20 
21     int getMin() {
22         return minElems.top();
23     }
24 private:
25     stack<int> elems;
26     stack<int> minElems;
27 };