PROBLEM STATEMENT
Binary strings, as most of us know, are composed solely of 0's and 1's.
Sometimes it is necessary to turn all the bits either on (1) or off (0).
However, sometimes it is not possible to just pick and flip individual bits. In
this hypothetical scenario, it is only possible to flip bits in a contiguous
segment which is a subset of the contiguous segment which was flipped
immediately prior to it. For example, if bits 2-4 are flipped, it is not legal
to flip bits 3-5 next, or bits 1-3. However, bits 3-4 or bits 2-3 would be
legal. The first segment to be flipped can be located anywhere in the sequence.
Create a class BitFlipper which contains a method minFlip which determines the
minimum number of bits that must be flipped under the above restriction in
order to get all the bits set to 0. For purposes of this problem, to flip a bit
means to change it from 0 to 1 or from 1 to 0.
DEFINITION
Class: BitFlipper
Method: minFlip
Parameters: String
Returns: int
Method signature (be sure it is declared public): int minFlip (String bits);
TopCoder will ensure the validity of the inputs. Inputs are valid if all of
the following criteria are met:
* bits will be between 0 and 50 characters in length, inclusive
* bits will contain only 1's and 0's.
EXAMPLES
Example 1:
bits = "00110".
By flipping bits 3-4, we get "00000". Method returns 2.
Example 2:
bits = "10110"
If we flip bits 1-4, we get "01000". Now we flip bit 2 and get "00000".
Method returns 4 + 1 = 5.
Example 3:
bits = "1001110001"
Flipping bits 1-10 yields "0110001110"
Now, flipping bits 2-9 yields "0001110000"
Again, flipping bits 4-6 yields "0000000000"
Method returns 10 + 8 + 3 = 21.
Example 4:
bits = "10001"
Method returns 8.
Example 5:
bits = "101010101"
Method returns 25.
Example 6:
bits = ""
Method returns 0.