Write a class StockSpanner which collects daily price quotes for some stock, and returns the span of that stock’s price for the current day.

The span of the stock’s price today is defined as the maximum number of consecutive days (starting from today and going backwards) for which the price of the stock was less than or equal to today’s price.

For example, if the price of a stock over the next 7 days were [100, 80, 60, 70, 60, 75, 85], then the stock spans would be [1, 1, 1, 2, 1, 4, 6].

739.Daily Temperatures 的题目原理是一样的，只是要求的是最小元素往右的最长 subarray，解法同上，只是此时需要从后往前遍历数组了，具体的代码可见: python版本c++版本go版本

## 拓展

$$\sum_{i=0}^{n-1} A[i]f[i]$$