5c50572476
* Adding doctests in simpson_rule.py * [pre-commit.ci] auto fixes from pre-commit.com hooks for more information, see https://pre-commit.ci * Update stock_span_problem.py * [pre-commit.ci] auto fixes from pre-commit.com hooks for more information, see https://pre-commit.ci * Update subset_generation.py * Update subset_generation.py * Update data_structures/stacks/stock_span_problem.py Co-authored-by: Christian Clauss <cclauss@me.com> * Update stock_span_problem.py * Update data_structures/stacks/stock_span_problem.py Co-authored-by: Christian Clauss <cclauss@me.com> * Update stock_span_problem.py * Update stock_span_problem.py * updating DIRECTORY.md * Update stock_span_problem.py * Update stock_span_problem.py * Update stock_span_problem.py * Update stock_span_problem.py --------- Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com> Co-authored-by: Christian Clauss <cclauss@me.com> Co-authored-by: Maxim Smolskiy <mithridatus@mail.ru> Co-authored-by: MaximSmolskiy <MaximSmolskiy@users.noreply.github.com>
74 lines
2.1 KiB
Python
74 lines
2.1 KiB
Python
"""
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The stock span problem is a financial problem where we have a series of n daily
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price quotes for a stock and we need to calculate span of stock's price for all n days.
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The span Si of the stock's price on a given day i is defined as the maximum
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number of consecutive days just before the given day, for which the price of the stock
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on the current day is less than or equal to its price on the given day.
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"""
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def calculate_span(price: list[int]) -> list[int]:
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"""
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Calculate the span values for a given list of stock prices.
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Args:
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price: List of stock prices.
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Returns:
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List of span values.
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>>> calculate_span([10, 4, 5, 90, 120, 80])
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[1, 1, 2, 4, 5, 1]
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>>> calculate_span([100, 50, 60, 70, 80, 90])
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[1, 1, 2, 3, 4, 5]
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>>> calculate_span([5, 4, 3, 2, 1])
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[1, 1, 1, 1, 1]
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>>> calculate_span([1, 2, 3, 4, 5])
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[1, 2, 3, 4, 5]
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>>> calculate_span([10, 20, 30, 40, 50])
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[1, 2, 3, 4, 5]
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>>> calculate_span([100, 80, 60, 70, 60, 75, 85])
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[1, 1, 1, 2, 1, 4, 6]
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"""
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n = len(price)
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s = [0] * n
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# Create a stack and push index of fist element to it
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st = []
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st.append(0)
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# Span value of first element is always 1
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s[0] = 1
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# Calculate span values for rest of the elements
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for i in range(1, n):
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# Pop elements from stack while stack is not
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# empty and top of stack is smaller than price[i]
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while len(st) > 0 and price[st[-1]] <= price[i]:
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st.pop()
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# If stack becomes empty, then price[i] is greater
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# than all elements on left of it, i.e. price[0],
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# price[1], ..price[i-1]. Else the price[i] is
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# greater than elements after top of stack
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s[i] = i + 1 if len(st) <= 0 else (i - st[-1])
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# Push this element to stack
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st.append(i)
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return s
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# A utility function to print elements of array
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def print_array(arr, n):
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for i in range(n):
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print(arr[i], end=" ")
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# Driver program to test above function
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price = [10, 4, 5, 90, 120, 80]
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# Calculate the span values
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S = calculate_span(price)
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# Print the calculated span values
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print_array(S, len(price))
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