Java 如何将两个或多个字符串数组列表排列组合成一个组合列表
我想得到多字符串arraylist的所有组合Java 如何将两个或多个字符串数组列表排列组合成一个组合列表,java,string,combinations,permutation,Java,String,Combinations,Permutation,我想得到多字符串arraylist的所有组合 String arr1[]={"red","green"} String arr2[]={"underline"} ArrayList a=get_Combination(arr1,arr2) 输入: array 1=["red","green","blue"]. array 2=["bold"]. array 3=["underline"].` 输出: 组合列表应该如下所示 [[red],[red,bold],[red,bold,underli
String arr1[]={"red","green"}
String arr2[]={"underline"}
ArrayList a=get_Combination(arr1,arr2)
输入:
array 1=["red","green","blue"].
array 2=["bold"].
array 3=["underline"].`
输出:
组合列表应该如下所示
[[red],[red,bold],[red,bold,underline],[underline],[underline,bold].......]
这是你想要的吗
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.stream.Collectors;
public class Combin {
public static void main(String[] args) {
// TODO Auto-generated method stub
final String[][] array = new String[][] {
new String[] {"red","green","blue"}
, new String[] {"bold"}
, new String[] {"underline"}
};
final List<String> list = combination(Arrays.asList(array));
list.stream()
.forEach(
System.out::println
)
;
}
static List<String> combination(
final List<String[]> array)
{
if(array == null || array.size() < 1) {
return Collections.<String>emptyList();
}
if(array.size() == 1) {
return Arrays.stream(array.get(0))
.collect(Collectors.toList())
;
}
if(array.size() == 2) {
List<String> list1 = Arrays.stream(array.get(0))
.collect(Collectors.toList())
;
List<String> list2 = Arrays.stream(array.get(1))
.collect(Collectors.toList())
;
final List<String> list3 = new ArrayList<>();
list1.stream()
.forEach(
s1 -> {
list2.stream()
.forEach(
s2 -> {
list3.add(s1 + ", " + s2);
}
);
}
)
;
final List<String> list = new ArrayList<>();
list.addAll(list1);
list.addAll(list2);
list.addAll(list3);
return list;
}
//length > 2
List<String> list = combination(array.subList(0, 2));
for(int i=2; i<array.size(); i++) {
List<String[]> newArrayList = new ArrayList<>();
newArrayList.add(list.toArray(new String[list.size()]));
newArrayList.add(array.get(i));
list = combination(newArrayList);
}
return list;
}
}
还请输入您试图获得理想输出的代码?它是失败的还是部分有效的?最好看看你的第一个方法,以帮助你提高它谢谢你!!但是,在android studio中,流函数需要至少24个api级别,还有其他方法吗?非常感谢您的帮助,尽管这正是我在寻找的stream forEach输出,将其更改为for循环,将流数组更改为list,只需自己将数组转换为list,请自己尝试
red
green
blue
bold
red, bold
green, bold
blue, bold
underline
red, underline
green, underline
blue, underline
bold, underline
red, bold, underline
green, bold, underline
blue, bold, underline