Change any bit of s in one operation. Return the fewest changes needed to obtain a string consisting of zero or more 0 characters followed by zero or more 1 characters.
Example 1:
Input: s = "1100"
Output: 2Explanation: Flip the first two bits to get "0000", or the last two to get "1111". A single flip cannot remove every 1-before-0 violation.
Example 2:
Input: s = "0000"
Output: 0Explanation: All bits are 0, which is already a valid monotone string with no trailing ones.
Example 3:
Input: s = "1111"
Output: 0Explanation: All bits are 1, which is already a valid monotone string with no leading zeros.
Constraints:
1 <= s.length <= 100000- Each character is
0or1.