Given a string, find the first non-repeating character in it and return it’s index. If it doesn’t exist, return -1.
Examples:
s = "leetcode"return 0.s = "loveleetcode",return 2.class Solution {public: int firstUniqChar(string s) { map<char, int> m; int pos = -1; for(int i = 0; i < s.length(); ++i){ if(m.count(s[i]) != 0) m[s[i]] = -1; else m[s[i]] = i; } for(auto itr = m.begin(); itr != m.end(); ++itr){ if(itr->second != -1){ if(pos == -1 || pos > itr->second) pos = itr->second; } } return pos; }};新聞熱點
疑難解答
