package main

import (
    "fmt"
    "math/rand"
    "time"
)

func main() {
    rand.Seed(time.Now().UnixNano())
    arr := []int{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
    c := Constructor(arr)
    fmt.Println(c.Shuffle())
}

type Solution struct {
    origin  []int
    shuffle []int
    N       int
}

func Constructor(nums []int) Solution {
    res := Solution{}
    res.origin = nums
    res.N = len(nums)
    res.shuffle = make([]int, res.N)
    for i := 0; i < res.N; i++ {
        res.shuffle[i] = res.origin[i]
    }
    return res
}

func (this *Solution) Reset() []int {
    return this.origin
}

func (this *Solution) Shuffle() []int {
    for i := this.N - 1; i >= 0; i-- {
        //int r = (int) (Math.random() * (i + 1));
        r := rand.Intn(i + 1)
        tmp := this.shuffle[r]
        this.shuffle[r] = this.shuffle[i]
        this.shuffle[i] = tmp
    }
    return this.shuffle
}