火车进站

package OJ;

import java.util.*;

public class Bully {

/*

* 火车进站

* 先全排列，再输出符合栈规则的项

*

* */

private static int cont = 1;

private static ArrayList<String> al = new ArrayList<String>();

public static void main(String[] args) {

Scanner sc = new Scanner(System.in);

while(sc.hasNext()){

int n = Integer.parseInt(sc.nextLine());//输入为火车的总数

int[] str = new int[100];

for(int i=0;i<n;i++)

str[i] = i+1;

perm(str,0,n);

}

}

private static void perm(int[] str, int k, int n) {

if(k==n-1)

print(str,n);//输出项

else{

int temp;

for(int i=k;i<n;i++){

temp = str[k];

str[k] = str[i];

str[i] = temp;

perm(str,k+1,n);

temp = str[i];

str[i] = str[k];

str[k] = temp;

}

}

}

private static void print(int[] str, int n) {

boolean flag = true;

int[] b = new int[2];

for(int i=0;i<n;i++){

int m = 0;

for(int j=i+1;j<n && flag;j++){

if(str[i]>str[j]){

if(m==0)

b[m++] = str[j];

else{

if(str[j]>b[0])

flag = false;

else

b[0] = str[j];

}

}

}

}

if(flag){

sop(cont++ + " ");

for(int i=0;i<n;i++){

sop(str[i]);

}

sop("\n");

}

}

public static void sop(Object o){

System.out.print(o);

}

}