Given a circular array (the next element of the last element is the first element of the array), print the Next Greater Number for every element. The Next Greater Number of a number x is the first greater number to its traversing-order next in the array, which means you could search circularly to find its next greater number. If it doesn’t exist, output -1 for this number.
Input: [1,2,1] Output: [2,-1,2] Explanation: The first 1's next greater number is 2; The number 2 can't find next greater number; The second 1's next greater number needs to search circularly, which is also 2.
Note: The length of given array won’t exceed 10000.
和Next Greater Element I类似，借助stack，通过比较、入栈和出栈更新数后面第一个大于这个数的数。不同的是不需要map，因为可以循环查找，所以最好还需要遍历一遍数组，代码如下：