def getPrevSmallerNumber(self, num):
#first find the non trailing 1
oneCounter = 0
pivot = -1
bitCounter = -1
foundZero = False
curNum = num
while curNum > 0:
bitCounter += 1
if curNum % 2 == 0:
foundZero = True
else:
if foundZero:
pivot = bitCounter
break
else:
oneCounter += 1
curNum = curNum // 2
if pivot == -1:
return None
#now we need to:
#reset the bit at pivot till start, add back oneCounter+1 "1"
temp = Generic.clearBitFromStart(num, pivot)
print(Generic.DecToBinaryString(temp))
setNum = (1 << oneCounter + 1) - 1
print(Generic.DecToBinaryString(setNum))
temp = temp | setNum
print(Generic.DecToBinaryString(temp))
return temp
def insertion(self, a, b, i, j):
if len(b) > j - i + 1:
raise IndexError
#Create mask of 0 from j -> i, rest should be 1 -> ~ (1 from i-j)
numA = Generic.BinaryStringToDec(a)
numB = Generic.BinaryStringToDec(b)
#Clear bit j->i of num A
mask = ~(Generic.clearBitFromStart(((1 << j + 1) - 1), i - 1))
numA = numA & mask
#shit left num b i bit
numB = numB << i
return Generic.DecToBinaryString(numA | numB)
import BitManipulation.Generic as Generic
class Solution:
def pairwiseSwap(self, num):
#Assume number is of type integer 32 bits
onlyEven = 0xAAAAAAAA
onlyOdd = 0x55555555
#calculate even and odd bit number
even = num & onlyEven
odd = num & onlyOdd
#shift right even + shiftleft odd
even = even >> 1
odd = odd << 1
return even | odd
if __name__ == '__main__':
bin = "110110101101100"
print(" " + bin)
num = Generic.BinaryStringToDec(bin)
A = Solution()
res = A.pairwiseSwap(num)
print(Generic.DecToBinaryString(res))
#Find number of bit needed to be flipped to turn a -> b
import BitManipulation.Generic as Generic
class Solution:
def conversion(self,a ,b):
res = 0
while a > 0 and b > 0:
if a%2 != b%2:
res += 1
a = a//2
b = b//2
while a>0:
if a%2 == 1:
res += 1
a = a//2
while b > 0:
if b%2 == 1:
res += 1
b = b//2
return res
if __name__ == '__main__':
a = 100
b = 15
print(Generic.DecToBinaryString(a))
print(Generic.DecToBinaryString(b))
A = Solution()
print(A.conversion(b,a))