Added Trailing Zero Algo (#12104)

* Added Trailing Zero Algo

Created an algorithm that return the trailing zeroes of a number

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* updating DIRECTORY.md

---------

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: cclauss <cclauss@users.noreply.github.com>

Author: 3 people

DIRECTORY.md

@@ -875,6 +875,7 @@
   * [Test Factorial](maths/test_factorial.py)
   * [Test Prime Check](maths/test_prime_check.py)
   * [Three Sum](maths/three_sum.py)
+  * [Trailing Zeroes](maths/trailing_zeroes.py)
   * [Trapezoidal Rule](maths/trapezoidal_rule.py)
   * [Triplet Sum](maths/triplet_sum.py)
   * [Twin Prime](maths/twin_prime.py)

maths/trailing_zeroes.py

@@ -0,0 +1,40 @@
+"""
+https://en.wikipedia.org/wiki/Trailing_zero
+"""
+
+
+def trailing_zeroes(num: int) -> int:
+    """
+    Finding the Trailing Zeroes i.e. zeroes present at the end of number
+    Args:
+        num: A integer.
+    Returns:
+        No. of zeroes in the end of an integer.
+
+    >>> trailing_zeroes(1000)
+    3
+    >>> trailing_zeroes(102983100000)
+    5
+    >>> trailing_zeroes(0)
+    1
+    >>> trailing_zeroes(913273)
+    0
+    """
+    ans = 0
+    if num < 0:
+        return -1
+    if num == 0:
+        return 1
+    while num > 0:
+        if num % 10 == 0:
+            ans += 1
+        else:
+            break
+        num /= 10
+    return ans
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()