991.py

'''
On a broken calculator that has a number showing on its display, we can perform two operations:

Double: Multiply the number on the display by 2, or;
Decrement: Subtract 1 from the number on the display.
Initially, the calculator is displaying the number X.

Return the minimum number of operations needed to display the number Y.



Example 1:

Input: X = 2, Y = 3
Output: 2
Explanation: Use double operation and then decrement operation {2 -> 4 -> 3}.
'''

classSolution(object):
defbrokenCalc(self, X, Y):
"""
 :type X: int
 :type Y: int
 :rtype: int
 """
ifX==Y:
return0
ifX>Y:
returnX-Y
if(Y%2==1):
return1+self.brokenCalc(X, Y+1)
else:
return1+self.brokenCalc(X, Y/2)