arr-search-binary

Efficient binary search utilities for sorted arrays, including variations like first & last occurrence, element count, and floor value search.

Installation

Install the package via npm:

npm i arr-search-binary

Usage

const asb = require('arr-search-binary');

const arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
console.log(asb.binarySearch(arr, 9));  // Output: 8

// OR use it like this:
console.log(asb.binarySearch([1, 2, 3, 4, 5], 3));  // Output: 2

API Reference

| Function | Description | Parameters | Returns | Example | |-----------------------------------|------------------------------------------------------------------|-------------------------------------------------|----------------------------------------------|---------------------------------------------------| | binarySearch(arr, target) | Standard binary search to find an element in a sorted array. | arr (sorted array), target (number to find) | Index of target or -1 if not found. | binarySearch([1, 2, 3, 4, 5], 3) → 2 | | firstOccurrence(arr, target) | Finds the first occurrence of target in a sorted array. | arr (sorted array), target (number to find) | Index of first occurrence or -1 if not found.| firstOccurrence([1, 2, 2, 3], 2) → 1 | | lastOccurrence(arr, target) | Finds the last occurrence of target in a sorted array. | arr (sorted array), target (number to find) | Index of last occurrence or -1 if not found. | lastOccurrence([1, 2, 2, 3], 2) → 2 | | countOccurrences(arr, target) | Counts occurrences of target in a sorted array. | arr (sorted array), target (number to count) | Number of times target appears. | countOccurrences([1, 2, 2, 3], 2) → 2 | | floorValue(arr, target) | Finds the largest element ≤ target. | arr (sorted array), target (number to find floor of) | Floor value or null if none exists. | floorValue([1, 3, 5, 7], 6) → 5 | | ceilValue(arr, target) | Finds the smallest element ≥ target. | arr (sorted array), target (number to find ceil of) | Ceil value or null if none exists. | ceilValue([1, 3, 5, 7], 6) → 7 | | searchInRotatedSortedArray(arr, target) | Finds target in a rotated sorted array. | arr (rotated sorted array), target (number to find) | Index of target or -1 if not found. | searchInRotatedSortedArray([4, 5, 6, 7, 0, 1, 2], 0) → 4 | | findRotationIndex(arr) | Finds the index where a sorted array was rotated. | arr (rotated sorted array) | Rotation index. | findRotationIndex([4, 5, 6, 7, 0, 1, 2]) → 4 | | minInRotatedSortedArray(arr) | Finds the minimum element in a rotated sorted array. | arr (rotated sorted array) | Minimum element. | minInRotatedSortedArray([4, 5, 6, 7, 0, 1, 2]) → 0| | maxInRotatedSortedArray(arr) | Finds the maximum element in a rotated sorted array. | arr (rotated sorted array) | Maximum element. | maxInRotatedSortedArray([4, 5, 6, 7, 0, 1, 2]) → 7| | findPeakElement(arr) | Finds a peak element where an element is greater than its neighbors. | arr (array) | A peak element. | findPeakElement([1, 3, 4, 3, 2]) → 4 | | findMountainPeak(arr) | Finds the peak in a mountain (bitonic) array. | arr (mountain array) | Index of the peak. | findMountainPeak([1, 3, 5, 4, 2]) → 2 | | searchInMountainArray(arr, target)| Searches for target in a mountain array. | arr (mountain array), target (number to find) | Index of target or -1 if not found. | searchInMountainArray([1, 3, 5, 4, 2], 4) → 3 | | squareRoot(n, precision) | Finds the square root of n using binary search. | n (number), precision (decimal places, default: 6) | Approximate square root. | squareRoot(9, 6) → 3.000000 | | nthRoot(n, k, precision) | Finds the kth root of n using binary search. | n (number), k (root degree), precision (decimal places, default: 6) | Approximate kth root. | nthRoot(27, 3, 6) → 3.000000 | | minInSortedRotatedDuplicates(arr) | Finds the minimum in a sorted, rotated array with duplicates. | arr (rotated sorted array with duplicates) | Minimum element. | minInSortedRotatedDuplicates([3, 3, 1, 3]) → 1 |