9286 - FirstUniqueCharIndex

9286 - FirstUniqueCharIndex

by jiangshan (@jiangshanmeta) #中等 #string

题目

Given a string s, find the first non-repeating character in it and return its index. If it does not exist, return -1. (Inspired by leetcode 387)

在 Github 上查看：https://tsch.js.org/9286/zh-CN

代码

/* _____________ 你的代码 _____________ */

type FirstUniqueCharIndex<
  T extends string,
  _Acc extends string[] = [],
> = T extends ''
  ? -1
  : T extends `${infer Head}${infer Rest}`
    ? Head extends _Acc[number]
      ? FirstUniqueCharIndex<Rest, [..._Acc, Head]>
      : Rest extends `${string}${Head}${string}`
        ? FirstUniqueCharIndex<Rest, [..._Acc, Head]>
        : _Acc['length']
    : never

测试用例

/* _____________ 测试用例 _____________ */
import type { Equal, Expect } from '@type-challenges/utils'

type cases = [
  Expect<Equal<FirstUniqueCharIndex<'leetcode'>, 0>>,
  Expect<Equal<FirstUniqueCharIndex<'loveleetcode'>, 2>>,
  Expect<Equal<FirstUniqueCharIndex<'aabb'>, -1>>,
  Expect<Equal<FirstUniqueCharIndex<''>, -1>>,
  Expect<Equal<FirstUniqueCharIndex<'aaa'>, -1>>,
]

相关链接

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