## C# || Online Stock Span – How To Get Daily Price Stock Quotes & Consecutive Day Span Using C#

The following is a module with functions which demonstrates how to get the daily price stock quotes & consecutive day span using C#.

1. Stock Spanner – Problem Statement

Design an algorithm that 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 backward) for which the stock price 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].

Implement the StockSpanner class:

• StockSpanner() Initializes the object of the class.
• int next(int price) Returns the span of the stock’s price given that today’s price is price.

Example 1:

``` Input: ["StockSpanner", "next", "next", "next", "next", "next", "next", "next"] [[], [100], [80], [60], [70], [60], [75], [85]] Output: [null, 1, 1, 1, 2, 1, 4, 6]```

``` ```

```Explanation: StockSpanner stockSpanner = new StockSpanner(); stockSpanner.next(100); // return 1 stockSpanner.next(80); // return 1 stockSpanner.next(60); // return 1 stockSpanner.next(70); // return 2 stockSpanner.next(60); // return 1 stockSpanner.next(75); // return 4, because the last 4 prices (including today's price of 75) were less than or equal to today's price. stockSpanner.next(85); // return 6 ```

2. Stock Spanner – Solution

The following is a solution which demonstrates how to get the daily price stock quotes & consecutive day span.

This solution uses the monotonic stack approach.

The idea of this solution is to have a stack of a pair to store the current price and the maximum number of consecutive days.

For each new price, we check the top of the stack and keep a running total of each previous consecutive day span found for all stock prices that are less than or equal to today’s price.

Then, we add today’s price and the current running consecutive day total to the stack.

``` 2. Stock Spanner - Solution C# // ============================================================================ // Author: Kenneth Perkins // Date: Nov 12, 2021 // Taken From: http://programmingnotes.org/ // File: Solution.cs // Description: Demonstrates how to get the daily price stock quotes day span // ============================================================================ public class StockSpanner { // Store the current price & maximum number of consecutive days Stack<KeyValuePair<int, int>> stack; public StockSpanner() { stack = new Stack<KeyValuePair<int, int>>(); } public int Next(int price) { var consecutiveDays = 1; // Compare current price with the item on the top of the stack while (stack.Count > 0 && stack.Peek().Key <= price) { // Get the previous consecutive day span and add to the current result consecutiveDays += stack.Peek().Value; stack.Pop(); } // Add the current price and consecutive day span to the stack stack.Push(new KeyValuePair<int, int>(price, consecutiveDays)); return consecutiveDays; } }// http://programmingnotes.org/ 123456789101112131415161718192021222324252627282930 // ============================================================================//    Author: Kenneth Perkins//    Date:   Nov 12, 2021//    Taken From: http://programmingnotes.org///    File:  Solution.cs//    Description: Demonstrates how to get the daily price stock quotes day span// ============================================================================public class StockSpanner {    // Store the current price & maximum number of consecutive days    Stack<KeyValuePair<int, int>> stack;     public StockSpanner() {        stack = new Stack<KeyValuePair<int, int>>();    }     public int Next(int price) {        var consecutiveDays = 1;         // Compare current price with the item on the top of the stack        while (stack.Count > 0 && stack.Peek().Key <= price) {            // Get the previous consecutive day span and add to the current result            consecutiveDays += stack.Peek().Value;            stack.Pop();        }        // Add the current price and consecutive day span to the stack        stack.Push(new KeyValuePair<int, int>(price, consecutiveDays));         return consecutiveDays;    }}// http://programmingnotes.org/ ```

QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

Once compiled, you should get this as your output for the example cases:

``` [null,1,1,1,2,1,4,6] ```