# 387. First Unique Character in a String """ given a string 's', find the first non-repeating character in it and return its index. if it does not exist, return -1 """ class Solution(object): def firstUniqChar(self, s): """ :type s: str :rtype: int """ m = {} for c in s: m[c] = m.get(c, 0) + 1 for i in range(len(s)): if m[s[i]] == 1: return i return -1 if __name__ == "__main__": obj = Solution() print(obj.firstUniqChar("leetcode")) print(obj.firstUniqChar("loveleetcode")) print(obj.firstUniqChar("aabb"))