/**
 * Created by tujietg on Nov 6, 2019
 */
public class No744 {
    public char nextGreatestLetter(char[] letters, char target) {
        int len = letters.length;
        int tarInt = target - 'A' + 1;
        int lerInt = letters[len - 1] - 'A' + 1;
        if (target == 'z' || tarInt >= lerInt) {
            return letters[0];
        }
        int i;
        for (i = 1; i < len; i++) {
            int leInt = letters[i - 1] - 'A' + 1;
            if (leInt > tarInt) {
                break;
            }
        }
        return letters[i - 1];
    }

}