A-M baby

Task/Gray-code/Python/gray-code-1.py

@@ -0,0 +1,17 @@
+>>> def int2bin(n):
+	'From positive integer to list of binary bits, msb at index 0'
+	if n:
+		bits = []
+		while n:
+			n,remainder = divmod(n, 2)
+			bits.insert(0, remainder)
+		return bits
+	else: return [0]
+
+	
+>>> def bin2int(bits):
+	'From binary bits, msb at index 0 to integer'
+	i = 0
+	for bit in bits:
+		i = i * 2 + bit
+	return i

Task/Gray-code/Python/gray-code-2.py

@@ -0,0 +1,7 @@
+>>> def bin2gray(bits):
+	return bits[:1] + [i ^ ishift for i, ishift in zip(bits[:-1], bits[1:])]
+
+>>> def gray2bin(bits):
+	b = [bits[0]]
+	for nextb in bits[1:]: b.append(b[-1] ^ nextb)
+	return b

Task/Gray-code/Python/gray-code-3.py

@@ -0,0 +1,27 @@
+>>> for i in range(16):
+	print('int:%2i -> bin:%12r -> gray:%12r -> bin:%12r -> int:%2i' %
+	      ( i,
+	        int2bin(i),
+	        bin2gray(int2bin(i)),
+	        gray2bin(bin2gray(int2bin(i))),
+	        bin2int(gray2bin(bin2gray(int2bin(i))))
+	      ))
+
+	
+int: 0 -> bin:         [0] -> gray:         [0] -> bin:         [0] -> int: 0
+int: 1 -> bin:         [1] -> gray:         [1] -> bin:         [1] -> int: 1
+int: 2 -> bin:      [1, 0] -> gray:      [1, 1] -> bin:      [1, 0] -> int: 2
+int: 3 -> bin:      [1, 1] -> gray:      [1, 0] -> bin:      [1, 1] -> int: 3
+int: 4 -> bin:   [1, 0, 0] -> gray:   [1, 1, 0] -> bin:   [1, 0, 0] -> int: 4
+int: 5 -> bin:   [1, 0, 1] -> gray:   [1, 1, 1] -> bin:   [1, 0, 1] -> int: 5
+int: 6 -> bin:   [1, 1, 0] -> gray:   [1, 0, 1] -> bin:   [1, 1, 0] -> int: 6
+int: 7 -> bin:   [1, 1, 1] -> gray:   [1, 0, 0] -> bin:   [1, 1, 1] -> int: 7
+int: 8 -> bin:[1, 0, 0, 0] -> gray:[1, 1, 0, 0] -> bin:[1, 0, 0, 0] -> int: 8
+int: 9 -> bin:[1, 0, 0, 1] -> gray:[1, 1, 0, 1] -> bin:[1, 0, 0, 1] -> int: 9
+int:10 -> bin:[1, 0, 1, 0] -> gray:[1, 1, 1, 1] -> bin:[1, 0, 1, 0] -> int:10
+int:11 -> bin:[1, 0, 1, 1] -> gray:[1, 1, 1, 0] -> bin:[1, 0, 1, 1] -> int:11
+int:12 -> bin:[1, 1, 0, 0] -> gray:[1, 0, 1, 0] -> bin:[1, 1, 0, 0] -> int:12
+int:13 -> bin:[1, 1, 0, 1] -> gray:[1, 0, 1, 1] -> bin:[1, 1, 0, 1] -> int:13
+int:14 -> bin:[1, 1, 1, 0] -> gray:[1, 0, 0, 1] -> bin:[1, 1, 1, 0] -> int:14
+int:15 -> bin:[1, 1, 1, 1] -> gray:[1, 0, 0, 0] -> bin:[1, 1, 1, 1] -> int:15
+>>>