# 387. First Unique Character in a String

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.

# Solution

Approach 1: two passes using a hashtable.

# Code (Python)

Approach 1:

class Solution:
    def firstUniqChar(self, s: str) -> int:
        if not s:
            return -1
        
        chars = {}
        for char in s:
            if char not in chars:
                chars[char] = 0
            chars[char] += 1
        
        for index, letter in enumerate(s):
            if chars[letter] == 1:
                return index
        
        return -1

# Code (C++)

Approach 1:

Approach 2: