Min Stack (LeetCode) tweak it to avoid Memory Limit Exceeded

 1 class MinStack {
 2 public:
 3     void push(int x) {
 4         if(values.empty())
 5         {
 6             values.push_back(x);
 7             min_indices.push_back(0);
 8         }
 9         else
10         {
11             if( x < values[min_indices.back()] )
12                 min_indices.push_back(values.size());
13             values.push_back(x);            
14         }
15         
16     }
17 
18     void pop() {        
19         values.pop_back();
20         if(values.size() == min_indices.back())
21             min_indices.pop_back();
22     }
23 
24     int top() {
25         return values.back();
26     }
27 
28     int getMin() {
29         return values[min_indices.back()];
30     }
31 private:
32     deque<int> values;
33     deque<deque<int>::size_type> min_indices;
34 };