guanghechen
@algorithm.ts/lower-bound
A typescript implementation of the lower bound algorithm.
The lower bound algorithm is desired to find the index of first elements which greater or equals than the target element.
Install
npm
npm install --save @algorithm.ts/lower-boundyarn
yarn add @algorithm.ts/lower-bounddeno
import lowerBound from 'https://raw.githubusercontent.com/guanghechen/algorithm.ts/main/packages/lower-bound/src/index.ts'
Usage
Basic
import lowerBound from '@algorithm.ts/lower-bound' // elements should be ordered. const elements: number[] = [2, 3, 7, 11, 19] // Find the index of elements which is the first element greater or equal than 8 // elements[3] = 11 >= 8 lowerBound(0, elements.length, x => elements[x] - 8) // => 3 // Find the index of elements which is the first element greater or equal than 3 // elements[1] = 3 >= 3 lowerBound(0, elements.length, x => elements[x] - 3) // => 1Complex
import lowerBound from '@algorithm.ts/lower-bound' const fruits = [ { type: 'orange', price: 3 }, { type: 'apple', price: 10 }, { type: 'banana', price: 10 }, { type: 'watermelon', price: 12 }, { type: 'lemon', price: 15 }, ] // Find the index of fruits which price is greater or equal than 10 lowerBound(0, fruits.length, x => fruits[x].price - 10) // => 1 // Find the index of fruits which price is greater or equal than 11 lowerBound(0, fruits.length, x => fruits[x].price - 11) // => 3Bigint
import { lowerBoundBigint } from '@algorithm.ts/lower-bound' lowerBoundBigint(-500000000000n, 5000000000n, x => x - 1n) // => 1n