Bulb Switcher IV

There is a room with n bulbs, numbered from 0 to n-1, arranged in a row from left to right. Initially all the bulbs are turned off.

Your task is to obtain the configuration represented by target where target[i] is '1' if the i-th bulb is turned on and is '0' if it is turned off.

You have a switch to flip the state of the bulb, a flip operation is defined as follows:

When any bulb is flipped it means that if it is 0 it changes to 1 and if it is 1 it changes to 0.

Return the minimum number of flips required to form target.

 

Example 1:

Input: target = "10111"
Output: 3
Explanation: Initial configuration "00000".
flip from the third bulb:  "00000" -> "00111"
flip from the first bulb:  "00111" -> "11000"
flip from the second bulb:  "11000" -> "10111"
We need at least 3 flip operations to form target.
Example 2:

Input: target = "101"
Output: 3
Explanation: "000" -> "111" -> "100" -> "101".

Example 3:

Input: target = "00000"
Output: 0

Example 4:

Input: target = "001011101"
Output: 5

 

Constraints:


Solution:

class Solution {
    public int minFlips(String target) {
        int count = 0;
        for (int i = 0; i < target.length(); i ++) {
            char c = target.charAt(i);
            if (count % 2 == 0 && c == '1' || count % 2 == 1 && c == '0') {
                count ++;
            }
        }
        return count;
    }
}