feat(work): add Minimum Window Substring & Basic Calculator solutions and implement StockSpanner algorithm

work/1/Medium/Stack/901.online-stock-span.py

@@ -24,12 +24,12 @@ less than or equal 8 for 3 consecutive days.
 
 Implement the StockSpanner class:
 
-	• StockSpanner() Initializes the object of the 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:
 
@@ -52,23 +52,27 @@ stockSpanner.next(75);  // return 4, because the last 4 prices
 price.
 stockSpanner.next(85);  // return 6
 
- 
+
 
 Constraints:
 
-	• 1 <= price <= 10^5
+        • 1 <= price <= 10^5
 
-	• At most 10^4 calls will be made to next.
+        • At most 10^4 calls will be made to next.
 """
 
-class StockSpanner:
 
+class StockSpanner:
     def __init__(self):
-        prices = []
-        
+        self.stack = []
 
     def next(self, price: int) -> int:
-        
+        ans = 1
+        while self.stack and self.stack[-1][0] <= price:
+            ans += self.stack.pop()[1]
+
+        self.stack.append([price, ans])
+        return ans
 
 
 # Your StockSpanner object will be instantiated and called as such: