LeetCode——Min Stack

Description：

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.

带有minimum element属性的stack操作。

class MinStack {
    public Node node = null;
    public void push(int x) {
        if(node == null) {
            node = new Node(x);
            node.min = x;
        }
        else {
            Node tNode = new Node(x);
            tNode.next = node;
            node = tNode;
            node.min = node.next.min < x ? node.next.min : x;
        }
    }

    public void pop() {
        node = node.next;
    }

    public int top() {
        return node.val;
    }

    public int getMin() {
        return node.min;
    }
}
class Node {
    int val;
    int min;
    Node next;
    public Node(int val) {
        this.val = val;
    }

}

好久没1A了。