leetcode-go/medium/384.shuffle-an-array.go

//package main

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

type Solution struct {
	arr []int
	sol []int
}

func Constructor(nums []int) Solution {
	solution := Solution{arr: nums}
	solution.sol = make([]int, len(nums))
	copy(solution.sol, nums)
	return solution
}

/** Resets the array to its original configuration and return it. */
func (this *Solution) Reset() []int {
	copy(this.sol, this.arr)
	return this.arr
}

/** Returns a random shuffling of the array. */
func (this *Solution) Shuffle() []int {
	n := len(this.arr)
	for i := 0; i < n; i++ {
		j := i + rand.Intn(n-i)
		this.sol[i], this.sol[j] = this.sol[j], this.sol[i]
	}
	return this.sol
}

//type tuple3 struct {
//	_1 int
//	_2 int
//	_3 int
//}

//func main() {
//	sol := Constructor([]int{1, 2, 3})
//	m := make(map[tuple3]int)
//	for i := 0; i < 10000; i++ {
//		arr := sol.Shuffle()
//		m[tuple3{arr[0], arr[1], arr[2]}]++
//	}
//	fmt.Println(m)
//}

/**
 * Your Solution object will be instantiated and called as such:
 * obj := Constructor(nums);
 * param_1 := obj.Reset();
 * param_2 := obj.Shuffle();
 */