September 2017 Update

Task/Fibonacci-sequence/Python/fibonacci-sequence-1.py

@@ -1,10 +1,5 @@
-from math import *
+def fib(n,x=[0,1]):
+   for i in range(abs(n)-1): x=[x[1],sum(x)]
+   return x[1]*pow(-1,abs(n)-1) if n<0 else x[1] if n else 0
 
-def analytic_fibonacci(n):
-  sqrt_5 = sqrt(5);
-  p = (1 + sqrt_5) / 2;
-  q = 1/p;
-  return int( (p**n + q**n) / sqrt_5 + 0.5 )
-
-for i in range(1,31):
-  print analytic_fibonacci(i),
+for i in range(-30,31): print fib(i),

Task/Fibonacci-sequence/Python/fibonacci-sequence-10.py

@@ -1,10 +1,7 @@
-def fib():
-    """Yield fib[n+1] + fib[n]"""
-    yield 1  # have to start somewhere
-    lhs, rhs = fib(), fib()
-    yield next(lhs) # move lhs one iteration ahead
-    while True:
-        yield next(lhs)+next(rhs)
+def fib(n, c={0:1, 1:1}):
+    if n not in c:
+        x = n // 2
+        c[n] = fib(x-1) * fib(n-x-1) + fib(x) * fib(n - x)
+    return c[n]
 
-f=fib()
-print [next(f) for _ in range(9)]
+fib(10000000)  # calculating it takes a few seconds, printing it takes eons

Task/Fibonacci-sequence/Python/fibonacci-sequence-11.py

@@ -1,11 +1,10 @@
-from itertools import islice
-
 def fib():
-    yield 0
-    yield 1
-    a, b = fib(), fib()
-    next(b)
+    """Yield fib[n+1] + fib[n]"""
+    yield 1  # have to start somewhere
+    lhs, rhs = fib(), fib()
+    yield next(lhs) # move lhs one iteration ahead
     while True:
-        yield next(a)+next(b)
+        yield next(lhs)+next(rhs)
 
-print(tuple(islice(fib(), 10)))
+f=fib()
+print [next(f) for _ in range(9)]

Task/Fibonacci-sequence/Python/fibonacci-sequence-12.py

@@ -0,0 +1,11 @@
+from itertools import islice
+
+def fib():
+    yield 0
+    yield 1
+    a, b = fib(), fib()
+    next(b)
+    while True:
+        yield next(a)+next(b)
+
+print(tuple(islice(fib(), 10)))

Task/Fibonacci-sequence/Python/fibonacci-sequence-2.py

@@ -1,8 +1,10 @@
-def fibIter(n):
-    if n < 2:
-        return n
-    fibPrev = 1
-    fib = 1
-    for num in xrange(2, n):
-        fibPrev, fib = fib, fib + fibPrev
-    return fib
+from math import *
+
+def analytic_fibonacci(n):
+  sqrt_5 = sqrt(5);
+  p = (1 + sqrt_5) / 2;
+  q = 1/p;
+  return int( (p**n + q**n) / sqrt_5 + 0.5 )
+
+for i in range(1,31):
+  print analytic_fibonacci(i),

Task/Fibonacci-sequence/Python/fibonacci-sequence-3.py

@@ -1,5 +1,8 @@
-def fibRec(n):
+def fibIter(n):
     if n < 2:
         return n
-    else:
-        return fibRec(n-1) + fibRec(n-2)
+    fibPrev = 1
+    fib = 1
+    for num in xrange(2, n):
+        fibPrev, fib = fib, fib + fibPrev
+    return fib

Task/Fibonacci-sequence/Python/fibonacci-sequence-4.py

@@ -1,11 +1,5 @@
-def fibMemo():
-    pad = {0:0, 1:1}
-    def func(n):
-        if n not in pad:
-            pad[n] = func(n-1) + func(n-2)
-        return pad[n]
-    return func
-
-fm = fibMemo()
-for i in range(1,31):
-    print fm(i),
+def fibRec(n):
+    if n < 2:
+        return n
+    else:
+        return fibRec(n-1) + fibRec(n-2)

Task/Fibonacci-sequence/Python/fibonacci-sequence-5.py

@@ -1,7 +1,11 @@
-def fibFastRec(n):
-    def fib(prvprv, prv, c):
-        if c < 1:
-            return prvprv
-        else:
-            return fib(prv, prvprv + prv, c - 1)
-    return fib(0, 1, n)
+def fibMemo():
+    pad = {0:0, 1:1}
+    def func(n):
+        if n not in pad:
+            pad[n] = func(n-1) + func(n-2)
+        return pad[n]
+    return func
+
+fm = fibMemo()
+for i in range(1,31):
+    print fm(i),

Task/Fibonacci-sequence/Python/fibonacci-sequence-6.py

@@ -1,5 +1,7 @@
-def fibGen(n):
-    a, b = 0, 1
-    while n>0:
-        yield a
-        a, b, n = b, a+b, n-1
+def fibFastRec(n):
+    def fib(prvprv, prv, c):
+        if c < 1:
+            return prvprv
+        else:
+            return fib(prv, prvprv + prv, c - 1)
+    return fib(0, 1, n)

Task/Fibonacci-sequence/Python/fibonacci-sequence-7.py

@@ -1,3 +1,5 @@
->>> [i for i in fibGen(11)]
-
-[0,1,1,2,3,5,8,13,21,34,55]
+def fibGen(n):
+    a, b = 0, 1
+    while n>0:
+        yield a
+        a, b, n = b, a+b, n-1

Task/Fibonacci-sequence/Python/fibonacci-sequence-8.py

@@ -1,30 +1,3 @@
-def prevPowTwo(n):
-    'Gets the power of two that is less than or equal to the given input'
-    if ((n & -n) == n):
-        return n
-    else:
-        n -= 1
-        n |= n >> 1
-        n |= n >> 2
-        n |= n >> 4
-        n |= n >> 8
-        n |= n >> 16
-        n += 1
-        return (n/2)
+>>> [i for i in fibGen(11)]
 
-def crazyFib(n):
-    'Crazy fast fibonacci number calculation'
-    powTwo = prevPowTwo(n)
-
-    q = r = i = 1
-    s = 0
-
-    while(i < powTwo):
-        i *= 2
-        q, r, s = q*q + r*r, r * (q + s), (r*r + s*s)
-
-    while(i < n):
-        i += 1
-        q, r, s = q+r, q, r
-
-    return q
+[0,1,1,2,3,5,8,13,21,34,55]

Task/Fibonacci-sequence/Python/fibonacci-sequence-9.py

@@ -1,7 +1,30 @@
-def fib(n, c={0:1, 1:1}):
-    if n not in c:
-        x = n // 2
-        c[n] = fib(x-1) * fib(n-x-1) + fib(x) * fib(n - x)
-    return c[n]
+def prevPowTwo(n):
+    'Gets the power of two that is less than or equal to the given input'
+    if ((n & -n) == n):
+        return n
+    else:
+        n -= 1
+        n |= n >> 1
+        n |= n >> 2
+        n |= n >> 4
+        n |= n >> 8
+        n |= n >> 16
+        n += 1
+        return (n/2)
 
-fib(10000000)  # calculating it takes a few seconds, printing it takes eons
+def crazyFib(n):
+    'Crazy fast fibonacci number calculation'
+    powTwo = prevPowTwo(n)
+
+    q = r = i = 1
+    s = 0
+
+    while(i < powTwo):
+        i *= 2
+        q, r, s = q*q + r*r, r * (q + s), (r*r + s*s)
+
+    while(i < n):
+        i += 1
+        q, r, s = q+r, q, r
+
+    return q