Method push

java/0155-min-stack.java:11–17

(int val)

    }

    public void push(int val) {
        stack.push(val);

        // The min stack may be empty, so we need to check it
        val = Math.min(val, minStack.isEmpty() ? val : minStack.peek());
        minStack.push(val);
    }

    public void pop() {
        stack.pop();