public static String[][] arithmetic(ArrayList list){
String arr=(String[])list.get(x)
//list的每一项都是一个String[],list有多少项不定，String[] 有多少维不定
//求数组间排列组合的结果
//如
list.get(0)=String[2]{ "1 ", "2 "};
list.get(1)=String[3]{ "a ", "b ", "c "};
//则返回：
1 a
1 b
1 c
2 a
2 b
2 c
//如
list.get(0)=String[2]{ "1 ", "2 "};
list.get(1)=String[3]{ "a ", "b ", "c "};
list.get(2)=String[2]{ "d ", "e "};
//则返回：
1 a d
1 a e
1 b d
1 b e
1 c d
1 c e
2 a d
2 a e
2 b d
2 b e
2 c d
2 c e
}
------解决方案--------------------
import java.util.ArrayList;
public class Test {
public static void main(String[] args)
{
ArrayList list=new ArrayList();
list.add(new String[]{ "1 ", "2 "});
list.add(new String[]{ "a ", "b ", "c "});
list.add(new String[]{ "d ", "e "});
Test test=new Test();
test.visit(1,new StringBuffer( " "),list);
}
public void visit(int depth,StringBuffer lastLevelStringBuff,ArrayList inputList){
String[] currentLevelString=(String[])inputList.get(depth-1);
if(depth==inputList.size())
{
for(int i=0;i <currentLevelString.length;i++)
{
StringBuffer sb=new StringBuffer().append(lastLevelStringBuff);
System.out.println(sb.append(currentLevelString[i]));
}
}
else
{
for(int i=0;i <currentLevelString.length;i++)
{
StringBuffer sb=new StringBuffer().append(lastLevelStringBuff);
visit(depth+1,sb.append(currentLevelString[i]).append( " "),inputList);
}
}
}
}