Given a string
s
, write a program to find the
first non-repeating character
in it and return its index.
Problem Note
- The string index starts from 0.
-
If there is no non-repeating character in the string
s
, return -1. -
You may assume the string
s
contains only lowercase characters.
Example 1
Input: s = "afteracademy"
Output: 1
Explanation: 'f' is the first non-repeating character in the string s. Hence, the output is index 1.
Example 2
Input: s = "mindorks"
Output: 0
Explanation: 'm' is the first non-repeating character in the string s. Hence, the output is index 0.
Example 3
Input: s = "abacdcd"
Output: -1
Explanation: In the string s, there is no non-repeating character. Hence, the output is -1.