LeetCode:744. 寻找比目标字母大的最小字母

class Solution { public: char nextGreatestLetter(vector<char>& letters, char target) { letters.push_back(letters[0]); if(target!='z') { for(int i=0;i<letters.size();i++) { if(letters[i]>target) { return letters[i]; } } return letters[0]; } else { return letters[0]; } return ' '; } };