Added largest pow of 2 le num (#9374)

Author: namansharma18899

bit_manipulation/largest_pow_of_two_le_num.py

@@ -0,0 +1,60 @@
+"""
+Author  : Naman Sharma
+Date    : October 2, 2023
+
+Task:
+To Find the largest power of 2 less than or equal to a given number.
+
+Implementation notes: Use bit manipulation.
+We start from 1 & left shift the set bit to check if (res<<1)<=number.
+Each left bit shift represents a pow of 2.
+
+For example:
+number: 15
+res:    1   0b1
+        2   0b10
+        4   0b100
+        8   0b1000
+        16  0b10000 (Exit)
+"""
+
+
+def largest_pow_of_two_le_num(number: int) -> int:
+    """
+    Return the largest power of two less than or equal to a number.
+
+    >>> largest_pow_of_two_le_num(0)
+    0
+    >>> largest_pow_of_two_le_num(1)
+    1
+    >>> largest_pow_of_two_le_num(-1)
+    0
+    >>> largest_pow_of_two_le_num(3)
+    2
+    >>> largest_pow_of_two_le_num(15)
+    8
+    >>> largest_pow_of_two_le_num(99)
+    64
+    >>> largest_pow_of_two_le_num(178)
+    128
+    >>> largest_pow_of_two_le_num(999999)
+    524288
+    >>> largest_pow_of_two_le_num(99.9)
+    Traceback (most recent call last):
+        ...
+    TypeError: Input value must be a 'int' type
+    """
+    if isinstance(number, float):
+        raise TypeError("Input value must be a 'int' type")
+    if number <= 0:
+        return 0
+    res = 1
+    while (res << 1) <= number:
+        res <<= 1
+    return res
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()