LeetCode in Kotlin
387. First Unique Character in a String
Easy
Given a string s, find the first non-repeating character in it and return its index. If it does not exist, return -1.
Example 1:
Input: s = “leetcode”
Output: 0
Example 2:
Input: s = “loveleetcode”
Output: 2
Example 3:
Input: s = “aabb”
Output: -1
Constraints:
1 <= s.length <= 105sconsists of only lowercase English letters.
Solution
class Solution {
fun firstUniqChar(s: String): Int {
var ans = Int.MAX_VALUE
var i = 'a'
while (i <= 'z') {
val ind = s.indexOf(i)
if (ind != -1 && ind == s.lastIndexOf(i)) {
ans = Math.min(ans, ind)
}
i++
}
return if (ans == Int.MAX_VALUE) {
-1
} else ans
}
}