insert new element to array and sort compare to search and sort when insert

insert_and_sort.go

package main

import (
	"math/rand"
	"sort"
	"testing"
	"time"
)

func randNums() []int {
	rand.Seed(time.Now().Unix())
	return rand.Perm(len)
}

var nums = randNums()
var len = 500

func insertSort1() {
	ss := make([]int, 0, len)
	for _, num := range nums {
		ss = append(ss, num)
	}
	sort.Ints(ss)
}

func BenchmarkSort1(b *testing.B) {
	for i := 0; i < b.N; i++ {
		insertSort1()
	}
}

func insertSort2() {
	ss := make([]int, 0, len)
	for _, num := range nums {
		i := sort.SearchInts(ss, num)
		ss = append(ss, 0)
		copy(ss[i+1:], ss[i:])
		ss[i] = num
	}
}

func BenchmarkSort2(b *testing.B) {
	for i := 0; i < b.N; i++ {
		insertSort2()
	}
}

100

goos: darwin
goarch: amd64
pkg: my-tests
cpu: Intel(R) Core(TM) i5-8279U CPU @ 2.40GHz
BenchmarkSort1-8   	  326121	      3391 ns/op
BenchmarkSort2-8   	  450127	      2657 ns/op
PASS
ok  	mytests	3.105s

200

goos: darwin
goarch: amd64
pkg: my-tests
cpu: Intel(R) Core(TM) i5-8279U CPU @ 2.40GHz
BenchmarkSort1-8   	  148509	      8000 ns/op
BenchmarkSort2-8   	  186192	      6509 ns/op
PASS
ok  	my-tests	2.991s

500

goos: darwin
goarch: amd64
pkg: my-tests
cpu: Intel(R) Core(TM) i5-8279U CPU @ 2.40GHz
BenchmarkSort1-8   	   42337	     27673 ns/op
BenchmarkSort2-8   	   39577	     31739 ns/op
PASS
ok  	my-tests	3.992s

1000

goos: darwin
goarch: amd64
pkg: my-tests
cpu: Intel(R) Core(TM) i5-8279U CPU @ 2.40GHz
BenchmarkSort1-8   	   17462	     67512 ns/op
BenchmarkSort2-8   	   14341	     85077 ns/op
PASS
ok  	my-tests	2.966s