A-M baby

Task/Greatest-common-divisor/Python/greatest-common-divisor-1.py

@@ -0,0 +1 @@
+from fractions import gcd

Task/Greatest-common-divisor/Python/greatest-common-divisor-2.py

@@ -0,0 +1,4 @@
+def gcd_iter(u, v):
+    while v:
+        u, v = v, u % v
+    return abs(u)

Task/Greatest-common-divisor/Python/greatest-common-divisor-3.py

@@ -0,0 +1,2 @@
+def gcd(u, v):
+    return gcd(v, u % v) if v else abs(u)

Task/Greatest-common-divisor/Python/greatest-common-divisor-4.py

@@ -0,0 +1,23 @@
+def gcd_bin(u, v):
+    u, v = abs(u), abs(v) # u >= 0, v >= 0
+    if u < v:
+        u, v = v, u # u >= v >= 0
+    if v == 0:
+        return u
+
+    # u >= v > 0
+    k = 1
+    while u & 1 == 0 and v & 1 == 0: # u, v - even
+        u >>= 1; v >>= 1
+        k <<= 1
+
+    t = -v if u & 1 else u
+    while t:
+        while t & 1 == 0:
+            t >>= 1
+        if t > 0:
+            u = t
+        else:
+            v = -t
+        t = u - v
+    return u * k