全排列-golang

在labuladong公众号看到一篇回溯法的模板，通过遍历决策树暴力递归。感觉比较简单直观，遂用golang试着写了一个全排列。

package main 

import(
    "fmt"
    )


func main(){
	nums := []int{1,2,3}
	var list List
	traceBack(nums, list)
	fmt.Println(res)
}

var res [][]int
type List []int
func (l *List) contains(x int)bool{
	for _, v := range *l{
		if v == x {
			return true
		}
	}
	return false
}

func (l *List) pop(){
	length := len(*l)
	*l = append((*l)[:length-1])
}


func traceBack(nums []int, list List) {
	if (cap(nums) == len(list)){
		res = append(res, list)
		return
	}
	for _, v := range nums{
		if list.contains(v){
			continue
		}
		list = append(list, v)
		traceBack(nums, list)
		list.pop()
	}
}