Merge branch 'TheAlgorithms:master' into master

Author: CaedenPH

DIRECTORY.md

@@ -729,6 +729,7 @@
   * [Maximum Subarray](other/maximum_subarray.py)
   * [Maximum Subsequence](other/maximum_subsequence.py)
   * [Nested Brackets](other/nested_brackets.py)
+  * [Number Container System](other/number_container_system.py)
   * [Password](other/password.py)
   * [Quine](other/quine.py)
   * [Scoring Algorithm](other/scoring_algorithm.py)

other/number_container_system.py

@@ -0,0 +1,180 @@
+"""
+A number container system that uses binary search to delete and insert values into
+arrays with O(n logn) write times and O(1) read times.
+
+This container system holds integers at indexes.
+
+Further explained in this leetcode problem
+> https://leetcode.com/problems/minimum-cost-tree-from-leaf-values
+"""
+
+
+class NumberContainer:
+    def __init__(self) -> None:
+        # numbermap keys are the number and its values are lists of indexes sorted
+        # in ascending order
+        self.numbermap: dict[int, list[int]] = {}
+        # indexmap keys are an index and it's values are the number at that index
+        self.indexmap: dict[int, int] = {}
+
+    def binary_search_delete(self, array: list | str | range, item: int) -> list[int]:
+        """
+        Removes the item from the sorted array and returns
+        the new array.
+
+        >>> NumberContainer().binary_search_delete([1,2,3], 2)
+        [1, 3]
+        >>> NumberContainer().binary_search_delete([0, 0, 0], 0)
+        [0, 0]
+        >>> NumberContainer().binary_search_delete([-1, -1, -1], -1)
+        [-1, -1]
+        >>> NumberContainer().binary_search_delete([-1, 0], 0)
+        [-1]
+        >>> NumberContainer().binary_search_delete([-1, 0], -1)
+        [0]
+        >>> NumberContainer().binary_search_delete(range(7), 3)
+        [0, 1, 2, 4, 5, 6]
+        >>> NumberContainer().binary_search_delete([1.1, 2.2, 3.3], 2.2)
+        [1.1, 3.3]
+        >>> NumberContainer().binary_search_delete("abcde", "c")
+        ['a', 'b', 'd', 'e']
+        >>> NumberContainer().binary_search_delete([0, -1, 2, 4], 0)
+        Traceback (most recent call last):
+            ...
+        ValueError: Either the item is not in the array or the array was unsorted
+        >>> NumberContainer().binary_search_delete([2, 0, 4, -1, 11], -1)
+        Traceback (most recent call last):
+            ...
+        ValueError: Either the item is not in the array or the array was unsorted
+        >>> NumberContainer().binary_search_delete(125, 1)
+        Traceback (most recent call last):
+            ...
+        TypeError: binary_search_delete() only accepts either a list, range or str
+        """
+        if isinstance(array, (range, str)):
+            array = list(array)
+        elif not isinstance(array, list):
+            raise TypeError(
+                "binary_search_delete() only accepts either a list, range or str"
+            )
+
+        low = 0
+        high = len(array) - 1
+
+        while low <= high:
+            mid = (low + high) // 2
+            if array[mid] == item:
+                array.pop(mid)
+                return array
+            elif array[mid] < item:
+                low = mid + 1
+            else:
+                high = mid - 1
+        raise ValueError(
+            "Either the item is not in the array or the array was unsorted"
+        )
+
+    def binary_search_insert(self, array: list | str | range, index: int) -> list[int]:
+        """
+        Inserts the index into the sorted array
+        at the correct position.
+
+        >>> NumberContainer().binary_search_insert([1,2,3], 2)
+        [1, 2, 2, 3]
+        >>> NumberContainer().binary_search_insert([0,1,3], 2)
+        [0, 1, 2, 3]
+        >>> NumberContainer().binary_search_insert([-5, -3, 0, 0, 11, 103], 51)
+        [-5, -3, 0, 0, 11, 51, 103]
+        >>> NumberContainer().binary_search_insert([-5, -3, 0, 0, 11, 100, 103], 101)
+        [-5, -3, 0, 0, 11, 100, 101, 103]
+        >>> NumberContainer().binary_search_insert(range(10), 4)
+        [0, 1, 2, 3, 4, 4, 5, 6, 7, 8, 9]
+        >>> NumberContainer().binary_search_insert("abd", "c")
+        ['a', 'b', 'c', 'd']
+        >>> NumberContainer().binary_search_insert(131, 23)
+        Traceback (most recent call last):
+            ...
+        TypeError: binary_search_insert() only accepts either a list, range or str
+        """
+        if isinstance(array, (range, str)):
+            array = list(array)
+        elif not isinstance(array, list):
+            raise TypeError(
+                "binary_search_insert() only accepts either a list, range or str"
+            )
+
+        low = 0
+        high = len(array) - 1
+
+        while low <= high:
+            mid = (low + high) // 2
+            if array[mid] == index:
+                # If the item already exists in the array,
+                # insert it after the existing item
+                array.insert(mid + 1, index)
+                return array
+            elif array[mid] < index:
+                low = mid + 1
+            else:
+                high = mid - 1
+
+        # If the item doesn't exist in the array, insert it at the appropriate position
+        array.insert(low, index)
+        return array
+
+    def change(self, index: int, number: int) -> None:
+        """
+        Changes (sets) the index as number
+
+        >>> cont = NumberContainer()
+        >>> cont.change(0, 10)
+        >>> cont.change(0, 20)
+        >>> cont.change(-13, 20)
+        >>> cont.change(-100030, 20032903290)
+        """
+        # Remove previous index
+        if index in self.indexmap:
+            n = self.indexmap[index]
+            if len(self.numbermap[n]) == 1:
+                del self.numbermap[n]
+            else:
+                self.numbermap[n] = self.binary_search_delete(self.numbermap[n], index)
+
+        # Set new index
+        self.indexmap[index] = number
+
+        # Number not seen before or empty so insert number value
+        if number not in self.numbermap:
+            self.numbermap[number] = [index]
+
+        # Here we need to perform a binary search insertion in order to insert
+        # The item in the correct place
+        else:
+            self.numbermap[number] = self.binary_search_insert(
+                self.numbermap[number], index
+            )
+
+    def find(self, number: int) -> int:
+        """
+        Returns the smallest index where the number is.
+
+        >>> cont = NumberContainer()
+        >>> cont.find(10)
+        -1
+        >>> cont.change(0, 10)
+        >>> cont.find(10)
+        0
+        >>> cont.change(0, 20)
+        >>> cont.find(10)
+        -1
+        >>> cont.find(20)
+        0
+        """
+        # Simply return the 0th index (smallest) of the indexes found (or -1)
+        return self.numbermap.get(number, [-1])[0]
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()

physics/speed_of_sound.py

@@ -0,0 +1,52 @@
+"""
+Title : Calculating the speed of sound
+
+Description :
+    The speed of sound (c) is the speed that a sound wave travels
+    per unit time (m/s). During propagation, the sound wave propagates
+    through an elastic medium. Its SI unit is meter per second (m/s).
+
+    Only longitudinal waves can propagate in liquids and gas other then
+    solid where they also travel in  transverse wave. The following Algo-
+    rithem calculates the speed of sound in fluid depanding on the bulk
+    module and the density of the fluid.
+
+    Equation for calculating speed od sound in fluid:
+    c_fluid = (K_s*p)**0.5
+
+    c_fluid: speed of sound in fluid
+    K_s: isentropic bulk modulus
+    p: density of fluid
+
+
+
+Source : https://en.wikipedia.org/wiki/Speed_of_sound
+"""
+
+
+def speed_of_sound_in_a_fluid(density: float, bulk_modulus: float) -> float:
+    """
+    This method calculates the speed of sound in fluid -
+    This is calculated from the other two provided values
+    Examples:
+    Example 1 --> Water 20°C: bulk_moduls= 2.15MPa, density=998kg/m³
+    Example 2 --> Murcery 20°: bulk_moduls= 28.5MPa, density=13600kg/m³
+
+    >>> speed_of_sound_in_a_fluid(bulk_modulus=2.15*10**9, density=998)
+    1467.7563207952705
+    >>> speed_of_sound_in_a_fluid(bulk_modulus=28.5*10**9, density=13600)
+    1447.614670861731
+    """
+
+    if density <= 0:
+        raise ValueError("Impossible fluid density")
+    if bulk_modulus <= 0:
+        raise ValueError("Impossible bulk modulus")
+
+    return (bulk_modulus / density) ** 0.5
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()