输入一个字符串，打印出该字符串中字符的所有排列。例如输入字符串abc，则输出由字符a、b、c所能排列出来的所有字符串abc、acb、bac、bca、cab和cba。
方法1：
public static void main(String[] args)
{
char[] c = new char[]{'a','b','c'};
int length = c.length;
int max = 1<<length;
for(int i = 1;i<=max;i++)
{
for(int j = 0;j<length;j++)
{
if(((1<<j)&i)!=0)
{
System.out.print(c[j]);
}
}
System.out.println("");
}
}
方法2：
public static void main(String[] args)
{
char[] c = new char[]{'a','b','c'};
for (int i = 1; i <= c.length; i++)
{
LinkedList<Character> list = new LinkedList<Character>();
iterator(c, 0, i, list);
}
}
public static void iterator(char[] c,int begin,int tag,LinkedList<Character> list)
{
if(tag == 0)
{
for (Character character : list)
{
System.out.print(character);
}
System.out.println();
return ;
}
if(begin == c.length)
return ;
list.add(new Character(c[begin]));
iterator(c, begin+1, tag-1, list);
list.remove(new Character(c[begin]));
iterator(c, begin+1 ,tag, list);
}