package web;
import java.util.ArrayList;
public class SubsetGenerator
{
int[] indexs = null;
int COUNT = 1;// choose how many to be combination
ArrayList<String> list = new ArrayList<String> ();
private String subsets;
public SubsetGenerator( String subsets )
{
this.subsets = subsets;
}
public ArrayList<String> getSubsets ( int... params )
{
if(params.length == 0)
{
indexs = new int[subsets.length ()];
params = new int[2];
params[0] = 0;
params[1] = -1;
list.add ("");
}
params[1]++;
if(params[1] > COUNT - 1)
{
return list;
}
for( indexs[params[1]] = params[0]; indexs[params[1]] < subsets.length (); indexs[params[1]]++ )
{
getSubsets (indexs[params[1]] + 1, params[1]);
if(params[1] == COUNT - 1)
{
String temp = "";
for( int i = COUNT - 1; i >= 0; i-- )
{
temp += subsets.charAt (indexs[params[1] - i]);
}
list.add (temp);
}
}
if(COUNT < subsets.length () && params[0] == 0)
{
COUNT++;
getSubsets (0, -1);
}
return list;
}
}
package web;
import java.util.ArrayList;
import java.util.Collections;
public class SubsetGeneratorTester
{
public static void main ( String[] args )
{
SubsetGenerator generator = new SubsetGenerator ("rum");
ArrayList<String> subsets = generator.getSubsets ();
Collections.sort (subsets);
if(!"[, m, r, rm, ru, rum, u, um]".equals (subsets.toString ()))
{
System.err.println ("Expected: [, m, r, rm, ru, rum, u, um]");
}
else
{
System.err.println ("Congratulations !");
System.out.println ("Your result is: " + subsets);
}
}
}
追问public ArrayList getSubsets ( int... params ) 不能有参数的
追答楼主,修改好了,查收