algorithm.md

Algorithm

Package algorithm implements some basic algorithm. eg. sort, search.

Source

• https://github.com/duke-git/lancet/blob/main/algorithm/sort.go
• https://github.com/duke-git/lancet/blob/main/algorithm/search.go
• https://github.com/duke-git/lancet/blob/main/algorithm/lru_cache.go

Usage

import (
    "github.com/duke-git/lancet/v2/algorithm"
)

Index

• BubbleSort
• InsertionSort
• SelectionSort
• ShellSort
• QuickSort
• HeapSort
• MergeSort
• CountSort
• BinarySearch
• BinaryIterativeSearch
• LinearSearch
• LRUCache

Documentation

BubbleSort

Sort slice with bubble sort algorithm. Param comparator should implements constraints.Comparator.

Signature:

func BubbleSort[T any](slice []T, comparator constraints.Comparator)

Example: Run

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/algorithm"
)

type intComparator struct{}

func (c *intComparator) Compare(v1 any, v2 any) int {
    val1, _ := v1.(int)
    val2, _ := v2.(int)

    //ascending order
    if val1 < val2 {
        return -1
    } else if val1 > val2 {
        return 1
    }
    return 0
}

func main() {
    numbers := []int{2, 1, 5, 3, 6, 4}
    comparator := &intComparator{}

    algorithm.BubbleSort(numbers, comparator)

    fmt.Println(numbers)

    // Output:
    // [1 2 3 4 5 6]
}

InsertionSort

Sort slice with insertion sort algorithm. Param comparator should implements constraints.Comparator.

Signature:

func InsertionSort[T any](slice []T, comparator constraints.Comparator)

Example: Run

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/algorithm"
)

type people struct {
    Name string
    Age  int
}

// PeopleAageComparator sort people slice by age field
type peopleAgeComparator struct{}

// Compare implements github.com/duke-git/lancet/constraints/constraints.go/Comparator
func (pc *peopleAgeComparator) Compare(v1 any, v2 any) int {
    p1, _ := v1.(people)
    p2, _ := v2.(people)

    //ascending order
    if p1.Age < p2.Age {
        return -1
    } else if p1.Age > p2.Age {
        return 1
    }

    return 0
}

func main() {
    peoples := []people{
        {Name: "a", Age: 20},
        {Name: "b", Age: 10},
        {Name: "c", Age: 17},
        {Name: "d", Age: 8},
        {Name: "e", Age: 28},
    }

    comparator := &peopleAgeComparator{}

    algorithm.InsertionSort(peoples, comparator)

    fmt.Println(peoples)

    // Output:
    // [{d 8} {b 10} {c 17} {a 20} {e 28}]
}

SelectionSort

Sort slice with selection sort algorithm. Param comparator should implements constraints.Comparator.

Signature:

func SelectionSort[T any](slice []T, comparator constraints.Comparator)

Example: Run

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/algorithm"
)

type intComparator struct{}

func (c *intComparator) Compare(v1 any, v2 any) int {
    val1, _ := v1.(int)
    val2, _ := v2.(int)

    //ascending order
    if val1 < val2 {
        return -1
    } else if val1 > val2 {
        return 1
    }
    return 0
}

func main() {
    numbers := []int{2, 1, 5, 3, 6, 4}
    comparator := &intComparator{}

    algorithm.SelectionSort(numbers, comparator)

    fmt.Println(numbers)

    // Output:
    // [1 2 3 4 5 6]
}

ShellSort

Sort slice with shell sort algorithm. Param comparator should implements constraints.Comparator.

Signature:

func ShellSort[T any](slice []T, comparator constraints.Comparator)

Example: Run

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/algorithm"
)

type intComparator struct{}

func (c *intComparator) Compare(v1 any, v2 any) int {
    val1, _ := v1.(int)
    val2, _ := v2.(int)

    //ascending order
    if val1 < val2 {
        return -1
    } else if val1 > val2 {
        return 1
    }
    return 0
}

func main() {
    numbers := []int{2, 1, 5, 3, 6, 4}
    comparator := &intComparator{}

    algorithm.ShellSort(numbers, comparator)

    fmt.Println(numbers)

    // Output:
    // [1 2 3 4 5 6]
}

QuickSort

Sort slice with quick sort algorithm. Param comparator should implements constraints.Comparator.

Signature:

func QuickSort[T any](slice []T comparator constraints.Comparator)

Example:Run

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/algorithm"
)

type intComparator struct{}

func (c *intComparator) Compare(v1 any, v2 any) int {
    val1, _ := v1.(int)
    val2, _ := v2.(int)

    //ascending order
    if val1 < val2 {
        return -1
    } else if val1 > val2 {
        return 1
    }
    return 0
}

func main() {
    numbers := []int{2, 1, 5, 3, 6, 4}
    comparator := &intComparator{}

    algorithm.QuickSort(numbers, comparator)

    fmt.Println(numbers)

    // Output:
    // [1 2 3 4 5 6]
}

HeapSort

Sort slice with heap sort algorithm. Param comparator should implements constraints.Comparator.

Signature:

func HeapSort[T any](slice []T, comparator constraints.Comparator)

Example: Run

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/algorithm"
)

type intComparator struct{}

func (c *intComparator) Compare(v1 any, v2 any) int {
    val1, _ := v1.(int)
    val2, _ := v2.(int)

    //ascending order
    if val1 < val2 {
        return -1
    } else if val1 > val2 {
        return 1
    }
    return 0
}

func main() {
    numbers := []int{2, 1, 5, 3, 6, 4}
    comparator := &intComparator{}

    algorithm.HeapSort(numbers, comparator)

    fmt.Println(numbers)

    // Output:
    // [1 2 3 4 5 6]
}

MergeSort

Sort slice with merge sort algorithm. Param comparator should implements constraints.Comparator.

Signature:

func MergeSort[T any](slice []T, comparator constraints.Comparator)

Example: Run

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/algorithm"
)

type intComparator struct{}

func (c *intComparator) Compare(v1 any, v2 any) int {
    val1, _ := v1.(int)
    val2, _ := v2.(int)

    //ascending order
    if val1 < val2 {
        return -1
    } else if val1 > val2 {
        return 1
    }
    return 0
}

func main() {
    numbers := []int{2, 1, 5, 3, 6, 4}
    comparator := &intComparator{}

    algorithm.MergeSort(numbers, comparator)

    fmt.Println(numbers)

    // Output:
    // [1 2 3 4 5 6]
}

CountSort

Sort slice with count sort algorithm. Param comparator should implements constraints.Comparator.

Signature:

func CountSort[T any](slice []T, comparator constraints.Comparator) []T

Example: Run

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/algorithm"
)


type intComparator struct{}

func (c *intComparator) Compare(v1 any, v2 any) int {
    val1, _ := v1.(int)
    val2, _ := v2.(int)

    //ascending order
    if val1 < val2 {
        return -1
    } else if val1 > val2 {
        return 1
    }
    return 0
}

func main() {
    numbers := []int{2, 1, 5, 3, 6, 4}
    comparator := &intComparator{}

    sortedNums := algorithm.CountSort(numbers, comparator)

    fmt.Println(sortedNums)

    // Output:
    // [1 2 3 4 5 6]
}

BinarySearch

BinarySearch search for target within a sorted slice, recursive call itself. If a target is found, the index of the target is returned. Else the function return -1.

Signature:

func BinarySearch[T any](sortedSlice []T, target T, lowIndex, highIndex int, comparator constraints.Comparator) int

Example: Run

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/algorithm"
)

type intComparator struct{}

func (c *intComparator) Compare(v1 any, v2 any) int {
    val1, _ := v1.(int)
    val2, _ := v2.(int)

    //ascending order
    if val1 < val2 {
        return -1
    } else if val1 > val2 {
        return 1
    }
    return 0
}

func main() {
    numbers := []int{1, 2, 3, 4, 5, 6, 7, 8}
    comparator := &intComparator{}

    result1 := algorithm.BinarySearch(numbers, 5, 0, len(numbers)-1, comparator)
    result2 := algorithm.BinarySearch(numbers, 9, 0, len(numbers)-1, comparator)

    fmt.Println(result1)
    fmt.Println(result2)

    // Output:
    // 4
    // -1
}

BinaryIterativeSearch

BinaryIterativeSearch search for target within a sorted slice, recursive call itself. If a target is found, the index of the target is returned. Else the function return -1.

Signature:

func BinaryIterativeSearch[T any](sortedSlice []T, target T, lowIndex, highIndex int, comparator constraints.Comparator) int

Example: Run

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/algorithm"
)

type intComparator struct{}

func (c *intComparator) Compare(v1 any, v2 any) int {
    val1, _ := v1.(int)
    val2, _ := v2.(int)

    //ascending order
    if val1 < val2 {
        return -1
    } else if val1 > val2 {
        return 1
    }
    return 0
}

func main() {
    numbers := []int{1, 2, 3, 4, 5, 6, 7, 8}
    comparator := &intComparator{}

    result1 := algorithm.BinaryIterativeSearch(numbers, 5, 0, len(numbers)-1, comparator)
    result2 := algorithm.BinaryIterativeSearch(numbers, 9, 0, len(numbers)-1, comparator)

    fmt.Println(result1)
    fmt.Println(result2)

    // Output:
    // 4
    // -1
}

LinearSearch

return the index of target in slice base on equal function.If a target is found, the index of the target is returned. Else the function return -1.

Signature:

func LinearSearch[T any](slice []T, target T, equal func(a, b T) bool) int

Example: Run

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/algorithm"
)

func main() {
    numbers := []int{3, 4, 5, 3, 2, 1}

    equalFunc := func(a, b int) bool {
        return a == b
    }

    result1 := algorithm.LinearSearch(numbers, 3, equalFunc)
    result2 := algorithm.LinearSearch(numbers, 6, equalFunc)

    fmt.Println(result1)
    fmt.Println(result2)

    // Output:
    // 0
    // -1
}

LRUCache

LRUCache implements mem cache with lru.

Signature:

func NewLRUCache[K comparable, V any](capacity int) *LRUCache[K, V]
func (l *LRUCache[K, V]) Get(key K) (V, bool)
func (l *LRUCache[K, V]) Put(key K, value V)
func (l *LRUCache[K, V]) Delete(key K) bool
func (l *LRUCache[K, V]) Len() int

Example: Run

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/algorithm"
)

func main() {
    cache := algorithm.NewLRUCache[int, int](2)

    cache.Put(1, 1)
    cache.Put(2, 2)

    result1, ok1 := cache.Get(1)
    result2, ok2 := cache.Get(2)
    result3, ok3 := cache.Get(3)

    fmt.Println(result1, ok1)
    fmt.Println(result2, ok2)
    fmt.Println(result3, ok3)

    fmt.Println(cache.Len())

    ok := cache.Delete(2)
    fmt.Println(ok)


    // Output:
    // 1 true
    // 2 true
    // 0 false
    // 2
    // true
}