Add sol3 for project_euler problem_03

project_euler/problem_03/sol3.py

@@ -0,0 +1,63 @@
+"""
+Problem:
+The prime factors of 13195 are 5,7,13 and 29. What is the largest prime factor
+of a given number N?
+
+e.g. for 10, largest prime factor = 5. For 17, largest prime factor = 17.
+"""
+
+
+def solution(n):
+    """Returns the largest prime factor of a given number n.
+
+    >>> solution(13195)
+    29
+    >>> solution(10)
+    5
+    >>> solution(17)
+    17
+    >>> solution(3.4)
+    3
+    >>> solution(0)
+    Traceback (most recent call last):
+        ...
+    ValueError: Parameter n must be greater or equal to one.
+    >>> solution(-17)
+    Traceback (most recent call last):
+        ...
+    ValueError: Parameter n must be greater or equal to one.
+    >>> solution([])
+    Traceback (most recent call last):
+        ...
+    TypeError: Parameter n must be int or passive of cast to int.
+    >>> solution("asd")
+    Traceback (most recent call last):
+        ...
+    TypeError: Parameter n must be int or passive of cast to int.
+    """
+    try:
+        n = int(n)
+    except (TypeError, ValueError) as e:
+        raise TypeError("Parameter n must be int or passive of cast to int.")
+    if n <= 0:
+        raise ValueError("Parameter n must be greater or equal to one.")
+    prime = 1
+    i = 2
+    ans = 0
+    if n==2:
+        return 2
+    while n > 2:
+        while n%i != 0:
+            i += 1
+        ans = i
+        while(n%i ==0):
+            n = n/i
+        i += 1
+
+    return int(ans)
+
+
+if __name__ == "__main__":
+    #print(solution(int(input().strip())))
+    import doctest
+    doctest.testmod()