psf/black code formatting (#1277)

data_structures/stacks/stock_span_problem.py

@@ -1,11 +1,13 @@
-'''
+"""
 The stock span problem is a financial problem where we have a series of n daily
 price quotes for a stock and we need to calculate span of stock's price for all n days.
 
 The span Si of the stock's price on a given day i is defined as the maximum
 number of consecutive days just before the given day, for which the price of the stock
 on the current day is less than or equal to its price on the given day.
-'''
+"""
+
+
 def calculateSpan(price, S):
 
     n = len(price)
@@ -21,14 +23,14 @@ def calculateSpan(price, S):
 
         # Pop elements from stack whlie stack is not
         # empty and top of stack is smaller than price[i]
-        while( len(st) > 0 and price[st[0]] <= price[i]):
+        while len(st) > 0 and price[st[0]] <= price[i]:
             st.pop()
 
         # If stack becomes empty, then price[i] is greater
         # than all elements on left of it, i.e. price[0],
         # price[1], ..price[i-1]. Else the price[i]  is
         # greater than elements after top of stack
-        S[i] = i+1 if len(st) <= 0 else (i - st[0])
+        S[i] = i + 1 if len(st) <= 0 else (i - st[0])
 
         # Push this element to stack
         st.append(i)
@@ -36,13 +38,13 @@ def calculateSpan(price, S):
 
 # A utility function to print elements of array
 def printArray(arr, n):
-    for i in range(0,n):
-        print(arr[i],end =" ")
+    for i in range(0, n):
+        print(arr[i], end=" ")
 
 
 # Driver program to test above function
 price = [10, 4, 5, 90, 120, 80]
-S = [0 for i in range(len(price)+1)]
+S = [0 for i in range(len(price) + 1)]
 
 # Fill the span values in array S[]
 calculateSpan(price, S)