week2 155. Min Stack

public class MinStack {
    Deque<Integer> pro; 
    Deque<Integer> min;
    

    /** initialize your data structure here. */
    public MinStack() {
    pro = new ArrayDeque<>();
    min = new ArrayDeque<>();
    }
    
    public void push(int x) {
        pro.addLast(x);
        if(min.isEmpty()){
            min.addLast(x);
        }else{
            min.addLast(min.peekLast() < x ? min.peekLast():x);
        }
    }
    
    public void pop() {
        pro.removeLast();
        min.removeLast();
    }
    
    public int top() {
        return pro.peekLast();
    }
    
    public int getMin() {
        return min.peekLast();
    }
}

/**
 * Your MinStack object will be instantiated and called as such:
 * MinStack obj = new MinStack();
 * obj.push(x);
 * obj.pop();
 * int param_3 = obj.top();
 * int param_4 = obj.getMin();
 */