LeetCode/java/minimum-changes-to-make-alternating-binary-string.java

class Solution {
    public int minOperations(String s) {
        int startingZero = 0;
        int startingOne = 0;

        for (int i = 0; i < s.length(); ++i) {
            char c = s.charAt(i);

            if (c != '0' + i % 2) {
                ++startingZero;
            }

            if (c != '0' + (i + 1) % 2) {
                ++startingOne;
            }
        }

        return Math.min(startingZero, startingOne);
    }
}