155. Min Stack

155. Min Stack

Total Accepted: 54402 Total Submissions: 259750 Difficulty: Easy

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.

 

class MinStack {
public:
    void push(int x) {
        datas.push(x);
        if(!min_elems.empty() && min_elems.top() < x){
            min_elems.push(min_elems.top());
        }else{
            min_elems.push(x);
        }
    }

    void pop() {
        datas.pop();
        min_elems.pop();
    }

    int top() {
        return datas.top();
    }

    int getMin() {
        return min_elems.top();
    }
private:
    stack<int> datas;
    stack<int> min_elems;
};

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