mirror of
https://github.com/autistic-symposium/master-algorithms-py.git
synced 2025-04-30 04:36:08 -04:00
bitwise scripts fixed
This commit is contained in:
parent
01703751f1
commit
91825867f6
18
src/bitwise/bit_operations/bit_array.py → src/bitwise/bit_array.py
Normal file → Executable file
18
src/bitwise/bit_operations/bit_array.py → src/bitwise/bit_array.py
Normal file → Executable file
@ -1,17 +1,16 @@
|
||||
#!/usr/bin/python3
|
||||
# mari von steinkirch @2013
|
||||
# steinkirch at gmail
|
||||
#!/usr/bin/env python
|
||||
|
||||
''' Example of how to use a bit array in python as a "counter" dict:
|
||||
__author__ = "bt3"
|
||||
|
||||
''' Example of how to use a bit array in python as a "counter" dict'''
|
||||
|
||||
def print_dupl_ba(l1):
|
||||
'''
|
||||
>>> l1 = [0, 1, 2, 3, 4, 2, 6, 7, 8, 9]
|
||||
>>> print_dupl_ba(l1)
|
||||
2
|
||||
'''
|
||||
'''
|
||||
|
||||
|
||||
|
||||
def print_dupl_ba(l1):
|
||||
bs = bytearray(10)
|
||||
for i in range(len(l1)):
|
||||
if i == l1[i]:
|
||||
@ -23,9 +22,6 @@ def print_dupl_ba(l1):
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
if __name__ == '__main__':
|
||||
import doctest
|
||||
doctest.testmod()
|
@ -1,40 +0,0 @@
|
||||
#!/usr/bin/python3
|
||||
# mari von steinkirch @2013
|
||||
# steinkirch at gmail
|
||||
|
||||
''' Clear a bit in a binary number. It is almost like the reverse of set bit:
|
||||
1) first create a number filled of 1s, with 0 at i (can create 0001000 and ~)
|
||||
2) AND the number so it clears the ith bit
|
||||
|
||||
>>> num = int('10010000', 2)
|
||||
>>> clear_bit(num, 4)
|
||||
'0b10000000'
|
||||
>>> num = int('10010011', 2)
|
||||
>>> clear_all_bits_from_i_to_0(num, 2)
|
||||
'0b10010000'
|
||||
>>> num = int('1110011', 2)
|
||||
>>> clear_all_bits_from_most_sig_to_1(num, 2)
|
||||
'0b11'
|
||||
'''
|
||||
|
||||
|
||||
|
||||
def clear_bit(num, i):
|
||||
mask = ~ (1 << i) # -0b10001
|
||||
return bin(num & mask)
|
||||
|
||||
|
||||
def clear_all_bits_from_i_to_0(num, i):
|
||||
mask = ~ ( (1 << (i+1)) - 1)
|
||||
return bin(num & mask)
|
||||
|
||||
|
||||
def clear_all_bits_from_most_sig_to_1(num, i):
|
||||
mask = ( 1 << i) -1
|
||||
return bin(num & mask)
|
||||
|
||||
|
||||
if __name__ == '__main__':
|
||||
import doctest
|
||||
doctest.testmod()
|
||||
|
@ -1,28 +0,0 @@
|
||||
#!/usr/bin/python3
|
||||
# mari von steinkirch @2013
|
||||
# steinkirch at gmail
|
||||
|
||||
''' Find how many bits a int has:
|
||||
1) Start with a mask of 1
|
||||
2) Mask with AND
|
||||
3) if result (if true): count += 1
|
||||
(obs: to find the int of a bin do int('1001', 2)) and to show in bin do bin(int))
|
||||
|
||||
>>> for i in range(17): print(find_bit_len(i))
|
||||
'''
|
||||
|
||||
|
||||
|
||||
def find_bit_len(int_num):
|
||||
lenght = 0
|
||||
while int_num:
|
||||
int_num >>= 1
|
||||
lenght += 1
|
||||
return lenght
|
||||
|
||||
|
||||
|
||||
if __name__ == '__main__':
|
||||
import doctest
|
||||
doctest.testmod()
|
||||
|
@ -1,41 +0,0 @@
|
||||
#!/usr/bin/python3
|
||||
# mari von steinkirch @2013
|
||||
# steinkirch at gmail
|
||||
|
||||
''' Get a bit in a binary number:
|
||||
1) Shifts 1 over by i bits
|
||||
2) make an AND with the number
|
||||
3) all the other than the bit at i are clean, now compare to 0
|
||||
4) if the new value is not 0, bit i is 1
|
||||
>>> num = int('0100100', 2)
|
||||
>>> get_bit(num, 0)
|
||||
0
|
||||
>>> get_bit(num, 1)
|
||||
0
|
||||
>>> get_bit(num, 2)
|
||||
1
|
||||
>>> get_bit(num, 3)
|
||||
0
|
||||
>>> get_bit(num, 4)
|
||||
0
|
||||
>>> get_bit(num, 5)
|
||||
1
|
||||
>>> get_bit(num, 6)
|
||||
0
|
||||
'''
|
||||
|
||||
|
||||
|
||||
def get_bit(num, i):
|
||||
mask = 1 << i
|
||||
return num & mask != 0
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
if __name__ == '__main__':
|
||||
import doctest
|
||||
doctest.testmod()
|
||||
|
@ -1,45 +0,0 @@
|
||||
#!/usr/bin/python3
|
||||
# mari von steinkirch @2013
|
||||
# steinkirch at gmail
|
||||
|
||||
''' This method returns the number of bits that are necessary to change to convert two
|
||||
numbers A and B:
|
||||
1) XOR
|
||||
2) count 1s
|
||||
|
||||
>>> a = int('10010000', 2)
|
||||
>>> b = int('01011010', 2)
|
||||
>>> count_bits_swap(a, b)
|
||||
4
|
||||
>>> count_bits_swap2(a, b)
|
||||
4
|
||||
'''
|
||||
|
||||
def count_bits_swap2(a, b):
|
||||
count = 0
|
||||
m = a^b
|
||||
while m:
|
||||
count +=1
|
||||
m = m & (m-1)
|
||||
return count
|
||||
|
||||
|
||||
|
||||
def count_bits_swap(a, b):
|
||||
m = a^b
|
||||
return count_1s(m)
|
||||
|
||||
|
||||
def count_1s(m):
|
||||
count = 0
|
||||
while m:
|
||||
if m& 1 :
|
||||
count +=1
|
||||
m >>= 1
|
||||
return count
|
||||
|
||||
|
||||
if __name__ == '__main__':
|
||||
import doctest
|
||||
doctest.testmod()
|
||||
|
@ -1,38 +0,0 @@
|
||||
#!/usr/bin/python3
|
||||
# mari von steinkirch @2013
|
||||
# steinkirch at gmail
|
||||
|
||||
''' Set a bit in a binary number:
|
||||
1) Shifts 1 over by i bits
|
||||
2) make an OR with the number, only the value at bit i will change and all the others bit
|
||||
of the mask are zero so will not affect the num
|
||||
>>> num = int('0100100', 2)
|
||||
>>> set_bit(num, 0)
|
||||
'0b100101'
|
||||
>>> set_bit(num, 1)
|
||||
'0b100110'
|
||||
>>> set_bit(num, 2) # nothing change
|
||||
'0b100100'
|
||||
>>> set_bit(num, 3)
|
||||
'0b101100'
|
||||
>>> set_bit(num, 4)
|
||||
'0b110100'
|
||||
>>> set_bit(num, 5) # nothing change
|
||||
'0b100100'
|
||||
'''
|
||||
|
||||
|
||||
|
||||
def set_bit(num, i):
|
||||
mask = 1 << i
|
||||
return bin( num | mask )
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
if __name__ == '__main__':
|
||||
import doctest
|
||||
doctest.testmod()
|
||||
|
@ -1,26 +0,0 @@
|
||||
#!/usr/bin/python3
|
||||
# mari von steinkirch @2013
|
||||
# steinkirch at gmail
|
||||
|
||||
''' This method merges set bit and clean bit:
|
||||
1) first clear the bit at i using a mask such as 1110111
|
||||
2) then shift the intended value v by i bits
|
||||
3) this will create a number with bit i to v and all other to 0
|
||||
4) finally update the ith bit with or
|
||||
|
||||
>>> num = int('10010000', 2)
|
||||
>>> update_bit(num, 2, 1)
|
||||
'0b10010100'
|
||||
'''
|
||||
|
||||
|
||||
|
||||
def update_bit(num, i, v):
|
||||
mask = ~ (1 << i)
|
||||
return bin( (num & mask) | (v << i) )
|
||||
|
||||
|
||||
if __name__ == '__main__':
|
||||
import doctest
|
||||
doctest.testmod()
|
||||
|
@ -6,7 +6,8 @@ __author__ = "bt3"
|
||||
1) Start with a mask of 1
|
||||
2) Mask with AND
|
||||
3) if result (if true): count += 1
|
||||
(obs: to find the int of a bin do int('1001', 2)) and to show in bin do bin(int))
|
||||
(obs: to find the int of a bin do int('1001', 2)) and to show in bin
|
||||
do bin(int))
|
||||
'''
|
||||
|
||||
|
||||
@ -22,4 +23,3 @@ if __name__ == '__main__':
|
||||
for i in range(17):
|
||||
print(find_bit_len(i))
|
||||
print i.bit_length()
|
||||
print
|
||||
|
22
src/bitwise/bit_operations/find_how_many_1_binary.py → src/bitwise/find_how_many_1_binary.py
Normal file → Executable file
22
src/bitwise/bit_operations/find_how_many_1_binary.py → src/bitwise/find_how_many_1_binary.py
Normal file → Executable file
@ -1,21 +1,22 @@
|
||||
#!/usr/bin/python3
|
||||
# mari von steinkirch @2013
|
||||
# steinkirch at gmail
|
||||
#!/usr/bin/env python
|
||||
|
||||
__author__ = "bt3"
|
||||
|
||||
''' Find how many 1s in the binary:
|
||||
1) Start with a mask of 1
|
||||
2) Mask with AND
|
||||
3) if result (if true): count += 1
|
||||
(obs: to find the int of a bin do int('1001', 2)) and to show in bin do bin(int))
|
||||
|
||||
>>> find_how_many_1_in_a_binary(9)
|
||||
2
|
||||
|
||||
(obs: to find the int of a bin do int('1001',
|
||||
2)) and to show in bin do bin(int))
|
||||
'''
|
||||
|
||||
|
||||
|
||||
def find_how_many_1_in_a_binary(n):
|
||||
'''
|
||||
>>> find_how_many_1_in_a_binary(9)
|
||||
2
|
||||
'''
|
||||
|
||||
counter = 0
|
||||
while n:
|
||||
if n & 1:
|
||||
@ -25,9 +26,6 @@ def find_how_many_1_in_a_binary(n):
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
if __name__ == '__main__':
|
||||
import doctest
|
||||
doctest.testmod()
|
12
src/bitwise/bit_operations/get_float_rep_bin.py → src/bitwise/get_float_rep_bin.py
Normal file → Executable file
12
src/bitwise/bit_operations/get_float_rep_bin.py → src/bitwise/get_float_rep_bin.py
Normal file → Executable file
@ -1,20 +1,22 @@
|
||||
#!/usr/bin/python3
|
||||
# mari von steinkirch @2013
|
||||
# steinkirch at gmail
|
||||
#!/usr/bin/env python
|
||||
|
||||
__author__ = "bt3"
|
||||
|
||||
''' Given a real number between 0 and 1 (eg: 0.72), this method print the binary
|
||||
representation. If the Number cannot be represented accurately in binary, with at
|
||||
most 32 chars, print error:
|
||||
'''
|
||||
|
||||
def get_float_rep(num):
|
||||
'''
|
||||
>>> get_float_rep(0.72)
|
||||
('Error 2', '.1011100001010001111010111000010')
|
||||
>>> get_float_rep(0.1)
|
||||
('Error 2', '.0001100110011001100110011001100')
|
||||
>>> get_float_rep(0.5)
|
||||
'.1'
|
||||
'''
|
||||
'''
|
||||
|
||||
def get_float_rep(num):
|
||||
if num >= 1 or num <= 0: return 'Error 1'
|
||||
result = '.'
|
||||
while num:
|
15
src/bitwise/bit_operations/insert_small_bin_into_big_bin.py → src/bitwise/insert_small_bin_into_big_bin.py
Normal file → Executable file
15
src/bitwise/bit_operations/insert_small_bin_into_big_bin.py → src/bitwise/insert_small_bin_into_big_bin.py
Normal file → Executable file
@ -1,22 +1,25 @@
|
||||
#!/usr/bin/python3
|
||||
# mari von steinkirch @2013
|
||||
# steinkirch at gmail
|
||||
#!/usr/bin/env python
|
||||
|
||||
__author__ = "bt3"
|
||||
|
||||
|
||||
''' Given two 32-bit numbers, N and M, and two bit positions, i and j, this
|
||||
method insert M into N such that M starts at bit j and ends at bit i:
|
||||
1) clear the bits j thru i in N'
|
||||
2) shift M so that it lines up with bits j thru i
|
||||
3) merge M and N
|
||||
'''
|
||||
|
||||
def insert_small_bin_into_big_bin(M, N, i, j):
|
||||
'''
|
||||
>>> N = 0b10000000000
|
||||
>>> M = 0b10011
|
||||
>>> j = 6
|
||||
>>> i = 2
|
||||
>>> insert_small_bin_into_big_bin(M, N, i, j)
|
||||
'0b10001001100'
|
||||
'''
|
||||
'''
|
||||
|
||||
def insert_small_bin_into_big_bin(M, N, i, j):
|
||||
allOnes = ~0
|
||||
left = allOnes << (j+1) # 1110000
|
||||
right = ( (1 << i) - 1) # 0000111
|
||||
@ -27,8 +30,6 @@ def insert_small_bin_into_big_bin(M, N, i, j):
|
||||
return bin( N_cleared | M_shifted)
|
||||
|
||||
|
||||
|
||||
|
||||
if __name__ == '__main__':
|
||||
import doctest
|
||||
doctest.testmod()
|
23
src/bitwise/bit_operations/next_with_same_num_1s.py → src/bitwise/next_with_same_num_1s.py
Normal file → Executable file
23
src/bitwise/bit_operations/next_with_same_num_1s.py → src/bitwise/next_with_same_num_1s.py
Normal file → Executable file
@ -1,21 +1,13 @@
|
||||
#!/usr/bin/python3
|
||||
# mari von steinkirch @2013
|
||||
# steinkirch at gmail
|
||||
#!/usr/bin/env python
|
||||
|
||||
__author__ = "bt3"
|
||||
|
||||
|
||||
''' Give a positive int, print the next smallest and next largest ints with
|
||||
same number of 1 bits.
|
||||
The brute force is:
|
||||
1) find number of 1 bits
|
||||
2) loop above and down until find same, checking for each
|
||||
|
||||
>>> num = 0b1001
|
||||
>>> next = '0b1010'
|
||||
>>> prev = '0b110'
|
||||
>>> print_prev_same_1s(num) == prev
|
||||
True
|
||||
>>> print_next_same_1s(num) == next
|
||||
True
|
||||
|
||||
'''
|
||||
|
||||
|
||||
@ -59,6 +51,9 @@ def find_num_1s(num):
|
||||
|
||||
|
||||
if __name__ == '__main__':
|
||||
import doctest
|
||||
doctest.testmod()
|
||||
num = 0b1001
|
||||
n = '0b1010'
|
||||
p = '0b110'
|
||||
print_prev_same_1s(num) == p
|
||||
print_next_same_1s(num) == n
|
||||
|
@ -8,18 +8,14 @@ __author__ = "bt3"
|
||||
1) Shifts 1 over by i bits
|
||||
2) make an OR with the number, only the value at bit i will change and all the others bit
|
||||
of the mask are zero so will not affect the num
|
||||
|
||||
'''
|
||||
|
||||
|
||||
|
||||
def set_bit(num, i):
|
||||
mask = 1 << i
|
||||
return bin( num | mask )
|
||||
|
||||
|
||||
|
||||
|
||||
if __name__ == '__main__':
|
||||
num = int('0100100', 2)
|
||||
print set_bit(num, 0) #'0b100101'
|
||||
|
@ -8,6 +8,10 @@ __author__ = "bt3"
|
||||
|
||||
|
||||
def swap_bit(a, b):
|
||||
'''
|
||||
>>> swap_bit(14, 73)
|
||||
(73, 14)
|
||||
'''
|
||||
a = a^b
|
||||
b = a^b
|
||||
a = a^b
|
||||
@ -15,7 +19,5 @@ def swap_bit(a, b):
|
||||
|
||||
|
||||
if __name__ == '__main__':
|
||||
a = 14
|
||||
b = 73
|
||||
a2, b2 = swap_bit(a, b)
|
||||
print "a was {0}, now it is {1}. \nb was {2}, now it is {3}".format(a, a2, b, b2)
|
||||
import doctest
|
||||
doctest.testmod()
|
23
src/bitwise/bit_operations/swap_odd_even.py → src/bitwise/swap_odd_even.py
Normal file → Executable file
23
src/bitwise/bit_operations/swap_odd_even.py → src/bitwise/swap_odd_even.py
Normal file → Executable file
@ -1,6 +1,7 @@
|
||||
#!/usr/bin/python3
|
||||
# mari von steinkirch @2013
|
||||
# steinkirch at gmail
|
||||
#!/usr/bin/env python
|
||||
|
||||
__author__ = "bt3"
|
||||
|
||||
|
||||
''' Swap odd and even bits in a smart way in a binary:
|
||||
1) first for odds, take n and move the odd:
|
||||
@ -8,17 +9,18 @@
|
||||
(b) shift by right by 1
|
||||
2) do the same to ints with 01010101
|
||||
3) merge
|
||||
|
||||
>>> num = 0b11011101
|
||||
>>> result = '0b1101110'
|
||||
>>> swap_odd_even(num) == result
|
||||
True
|
||||
|
||||
'''
|
||||
|
||||
|
||||
|
||||
def swap_odd_even(num):
|
||||
'''
|
||||
>>> num = 0b11011101
|
||||
>>> result = '0b1101110'
|
||||
>>> swap_odd_even(num) == result
|
||||
True
|
||||
'''
|
||||
|
||||
mask_odd = 0xAA # 0b10101010
|
||||
mask_even = 0x55 # 0b1010101
|
||||
odd = num & mask_odd
|
||||
@ -29,9 +31,6 @@ def swap_odd_even(num):
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
if __name__ == '__main__':
|
||||
import doctest
|
||||
doctest.testmod()
|
@ -1,8 +1,6 @@
|
||||
#!/usr/bin/python
|
||||
|
||||
__author__ = "Mari Wahl"
|
||||
__email__ = "marina.w4hl@gmail.com"
|
||||
#!/usr/bin/env python
|
||||
|
||||
__author__ = "bt3"
|
||||
|
||||
|
||||
def bubble_sort(seq):
|
||||
|
@ -1,7 +1,6 @@
|
||||
#!/usr/bin/python
|
||||
#!/usr/bin/env python
|
||||
|
||||
__author__ = "Mari Wahl"
|
||||
__email__ = "marina.w4hl@gmail.com"
|
||||
__author__ = "bt3"
|
||||
|
||||
|
||||
|
||||
|
@ -1,8 +1,6 @@
|
||||
#!/usr/bin/python
|
||||
|
||||
__author__ = "Mari Wahl"
|
||||
__email__ = "marina.w4hl@gmail.com"
|
||||
#!/usr/bin/env python
|
||||
|
||||
__author__ = "bt3"
|
||||
|
||||
|
||||
def gnome_sort(seq):
|
||||
|
@ -1,7 +1,6 @@
|
||||
#!/usr/bin/python
|
||||
#!/usr/bin/env python
|
||||
|
||||
__author__ = "Mari Wahl"
|
||||
__email__ = "marina.w4hl@gmail.com"
|
||||
__author__ = "bt3"
|
||||
|
||||
|
||||
class Heap(object):
|
||||
|
@ -1,7 +1,6 @@
|
||||
#!/usr/bin/python
|
||||
#!/usr/bin/env python
|
||||
|
||||
__author__ = "Mari Wahl"
|
||||
__email__ = "marina.w4hl@gmail.com"
|
||||
__author__ = "bt3"
|
||||
|
||||
|
||||
''' Heapsort using Pythons libraries'''
|
||||
|
@ -1,7 +1,6 @@
|
||||
#!/usr/bin/python
|
||||
#!/usr/bin/env python
|
||||
|
||||
__author__ = "Mari Wahl"
|
||||
__email__ = "marina.w4hl@gmail.com"
|
||||
__author__ = "bt3"
|
||||
|
||||
|
||||
|
||||
|
@ -1,7 +1,7 @@
|
||||
#!/usr/bin/python
|
||||
#!/usr/bin/env python
|
||||
|
||||
__author__ = "bt3"
|
||||
|
||||
__author__ = "Mari Wahl"
|
||||
__email__ = "marina.w4hl@gmail.com"
|
||||
|
||||
|
||||
|
||||
|
@ -1,7 +1,6 @@
|
||||
#!/usr/bin/python
|
||||
#!/usr/bin/env python
|
||||
|
||||
__author__ = "Mari Wahl"
|
||||
__email__ = "marina.w4hl@gmail.com"
|
||||
__author__ = "bt3"
|
||||
|
||||
|
||||
''' Some examples of how to implement Quick Sort in Python
|
||||
|
@ -1,7 +1,6 @@
|
||||
#!/usr/bin/python
|
||||
#!/usr/bin/env python
|
||||
|
||||
__author__ = "Mari Wahl"
|
||||
__email__ = "marina.w4hl@gmail.com"
|
||||
__author__ = "bt3"
|
||||
|
||||
|
||||
def selection_sort(seq):
|
||||
|
@ -1,7 +1,7 @@
|
||||
#!/usr/bin/python
|
||||
#!/usr/bin/env python
|
||||
|
||||
__author__ = "bt3"
|
||||
|
||||
__author__ = "Mari Wahl"
|
||||
__email__ = "marina.w4hl@gmail.com"
|
||||
|
||||
''' A method to sort an array so that all the anagrams are together. Since we only
|
||||
want the anagrams to be grouped, we can use a dictionary for this task. This
|
||||
|
Loading…
x
Reference in New Issue
Block a user