diff --git a/DIRECTORY.md b/DIRECTORY.md
index 41a2d2e9af03..2df9d56e99b7 100644
--- a/DIRECTORY.md
+++ b/DIRECTORY.md
@@ -725,6 +725,7 @@
     * [Secant Method](maths/numerical_analysis/secant_method.py)
     * [Simpson Rule](maths/numerical_analysis/simpson_rule.py)
     * [Square Root](maths/numerical_analysis/square_root.py)
+    * [Weierstrass Method](maths/numerical_analysis/weierstrass_method.py)
   * [Odd Sieve](maths/odd_sieve.py)
   * [Perfect Cube](maths/perfect_cube.py)
   * [Perfect Number](maths/perfect_number.py)
diff --git a/data_structures/stacks/stock_span_problem.py b/data_structures/stacks/stock_span_problem.py
index 5efe58d25798..74c2636784e2 100644
--- a/data_structures/stacks/stock_span_problem.py
+++ b/data_structures/stacks/stock_span_problem.py
@@ -8,8 +8,29 @@
 """
 
 
-def calculation_span(price, s):
+def calculate_span(price: list[int]) -> list[int]:
+    """
+    Calculate the span values for a given list of stock prices.
+    Args:
+        price: List of stock prices.
+    Returns:
+        List of span values.
+
+    >>> calculate_span([10, 4, 5, 90, 120, 80])
+    [1, 1, 2, 4, 5, 1]
+    >>> calculate_span([100, 50, 60, 70, 80, 90])
+    [1, 1, 2, 3, 4, 5]
+    >>> calculate_span([5, 4, 3, 2, 1])
+    [1, 1, 1, 1, 1]
+    >>> calculate_span([1, 2, 3, 4, 5])
+    [1, 2, 3, 4, 5]
+    >>> calculate_span([10, 20, 30, 40, 50])
+    [1, 2, 3, 4, 5]
+    >>> calculate_span([100, 80, 60, 70, 60, 75, 85])
+    [1, 1, 1, 2, 1, 4, 6]
+    """
     n = len(price)
+    s = [0] * n
     # Create a stack and push index of fist element to it
     st = []
     st.append(0)
@@ -21,18 +42,20 @@ def calculation_span(price, s):
     for i in range(1, n):
         # Pop elements from stack while 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[-1]] <= 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[-1])
 
         # Push this element to stack
         st.append(i)
 
+    return s
+
 
 # A utility function to print elements of array
 def print_array(arr, n):
@@ -42,10 +65,9 @@ def print_array(arr, n):
 
 # Driver program to test above function
 price = [10, 4, 5, 90, 120, 80]
-S = [0 for i in range(len(price) + 1)]
 
-# Fill the span values in array S[]
-calculation_span(price, S)
+# Calculate the span values
+S = calculate_span(price)
 
 # Print the calculated span values
 print_array(S, len(price))