// 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.
// Note: You may assume the string contain only lowercase letters.

@@ -262,8 +262,60 @@
 etters.%0A
+%0A/**%0A * @param %7Bstring%7D s%0A * @return %7Bnumber%7D%0A */%0A%0A%0A

add params