例如我输入2
下面能输入
1 2
2 1
或者输入3
3 2 1
1 2 3
1 3 2
我写了一个简易的程序，看看下面代码对你有没有帮助：
public class ArrayTest {
public static void main(String[] args) {
//获取数组长度
System.out.println("请输入数组长度：");
Scanner scanner = new Scanner(System.in);
int arrayLength = scanner.nextInt();
//生成数组
System.out.println("请输入数组内容，以回车分隔：");
String[] arr = new String[arrayLength];
//录入数组内容
for(int i=0;i<arr.length;i++){
arr[i] = scanner.next();
}
//打印数组内容
for(int i=0;i<arr.length;i++){
System.out.print(arr[i] + "\t");
}
}
}
public class permutate {
public static int total = 0;
public static void swap(String[] str, int i, int j)
{
String temp = new String();
temp = str[i];
str[i] = str[j];
str[j] = temp;
}
public static void arrange (String[] str, int st, int len)
{
if (st == len - 1)
{
for (int i = 0; i < len; i ++)
{
System.out.print(str[i]+ " ");
}
System.out.println();
total++;
}
else
{
for (int i = st; i < len; i ++)
{
swap(str, st, i);
arrange(str, st + 1, len);
swap(str, st, i);
}
}
}
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
String str[] = {"a","b","c"}; //你修改为 1 2 3
arrange(str, 0, str.length);
System.out.println(total);
}
}