2022-9-13

算法

• 814二叉树剪枝

1. 设置虚拟节点，因为root节点可能被消除，也为了统一dfs的逻辑
2. 判断子节点和本身和为0，就直接删除

ts

Includes

// ============= Test Cases =============
import type { Equal, Expect } from './test-utils'

type cases = [
  Expect<Equal<Includes<['Kars', 'Esidisi', 'Wamuu', 'Santana'], 'Kars'>, true>>,
  Expect<Equal<Includes<['Kars', 'Esidisi', 'Wamuu', 'Santana'], 'Dio'>, false>>,
  Expect<Equal<Includes<[1, 2, 3, 5, 6, 7], 7>, true>>,
  Expect<Equal<Includes<[1, 2, 3, 5, 6, 7], 4>, false>>,
  Expect<Equal<Includes<[1, 2, 3], 2>, true>>,
  Expect<Equal<Includes<[1, 2, 3], 1>, true>>,
  Expect<Equal<Includes<[{}], { a: 'A' }>, false>>,
  Expect<Equal<Includes<[boolean, 2, 3, 5, 6, 7], false>, false>>,
  Expect<Equal<Includes<[true, 2, 3, 5, 6, 7], boolean>, false>>,
  Expect<Equal<Includes<[false, 2, 3, 5, 6, 7], false>, true>>,
  Expect<Equal<Includes<[{ a: 'A' }], { readonly a: 'A' }>, false>>,
  Expect<Equal<Includes<[{ readonly a: 'A' }], { a: 'A' }>, false>>,
  Expect<Equal<Includes<[1], 1 | 2>, false>>,
  Expect<Equal<Includes<[1 | 2], 1>, false>>,
  Expect<Equal<Includes<[null], undefined>, false>>,
  Expect<Equal<Includes<[undefined], null>, false>>,
]


// ============= Your Code Here =============
// 使用infer推断分出First和Rest,配合递归实现遍历
// Equal可以替换更底层的实现
// type Equal<X, Y> = (<T>() => T extends X ? 1 : 2) extends <T>() => T extends Y ? 1 : 2 ? true : false

type Includes<T extends readonly any[], U> = T extends [infer First, ...infer Rest] ? Equal<First, U> extends true ? true : Includes<Rest, U>: false