题目描述

fmt会超时

样例

package main

import (
    "fmt"
    "strconv"
)

var n int

func dfs(isUsed []int, currentPath string) {
    if len(currentPath) == n*2 {
        fmt.Println(currentPath)
        return
    }
    for i := 1; i <= n; i++ {
        if isUsed[i] == 1 {
            continue
        }
        isUsed[i] = 1
        currentPath += strconv.Itoa(i) + " "
        dfs(isUsed, currentPath)
        currentPath = currentPath[:len(currentPath)-2]
        isUsed[i] = 0
    }
}

func main() {
    fmt.Scanf("%d", &n)
    dfs(make([]int, n+1), "")
}