Golang functions to work with sorted array by binary search.

ordered_int.go

package main

import (
	"fmt"
	"sort"
)

func OrderedInsert(a []int, j int) []int {
	n := len(a)
	if n == 0 {
		return append(a, j)
	}

	i := sort.Search(n, func(i int) bool { return a[i] >= j })
	return append(a[:i], append([]int{j}, a[i:]...)...)
}

func OrderedSearch(a []int, j int) (int, bool) {
	n := len(a)
	i := sort.Search(n, func(i int) bool { return a[i] >= j })
	if i == n || a[i] != j {  // not found
		return 0, false
	}
	return i, true
}

func OrderedHas(a []int, j int) bool {
	n := len(a)
	i := sort.Search(n, func(i int) bool { return a[i] >= j })
	if i == n || a[i] != j {  // not found
		return false
	}
	return true
}

func OrderedDelete(a []int, i int) []int {
	return append(a[:i], a[i+1:]...)
}

func main() {
	var a []int
	a = OrderedInsert(a, 1)
	fmt.Println(a)
	a = OrderedInsert(a, 5)
	fmt.Println(a)
	a = OrderedInsert(a, 3)
	fmt.Println(a)
	a = OrderedInsert(a, 2)
	fmt.Println(a)
	a = OrderedInsert(a, 4)
	fmt.Println(a)
	a = OrderedInsert(a, 0)
	fmt.Println(a)
	a = OrderedInsert(a, 6)
	fmt.Println(a)
}