java 把一个大的数组按照元素数量拆分为多个小的数组

比如需要把数组

['a','b','c','d','f']，按照每3个为一组拆分为多个数组，如下

['a','b','c'],['a','b','d'],['a','b','f'],['a','c','d'],['a','c',''f],['a','d','f']
['b','c','d'], ['b','c','f'], ['b','d','f']
['c','d','f']

 

直接上代码

 

/*
     * @Author gao
     * @Description //把一个集合中的元素，按照指定传入的needNum的数量再拆分为多个小的集合
     * ['a','b','c','d','f'],假设传入的needNum为3，则结果为
     * ['a','b','c'],['a','b','d'],['a','b','f'],['a','c','d'],['a','c',''f],['a','d','f']
     * ['b','c','d'], ['b','c','f'], ['b','d','f']
     * ['c','d','f']
     * @Param [addlist, begin, needNum, strings, result]
     * @return void
     **/
    public static void sortCompareData(List<String> addlist, int begin, int needNum, String [] strings, List<List<String>> result){
        for (int i = begin; i < strings.length; i++) {
            addlist.add(strings[i]);
            if (addlist.size() == needNum) {
                //放到新集合中，防止下面的集合操作影响已存储数据
                result.add(new ArrayList<>(addlist));
                //移除掉当前位置的元素
                addlist.remove(addlist.size()-1);
            } else {
                sortCompareData(addlist,i+1,needNum,strings,result);
                //移除掉当前位置的元素
                addlist.remove(addlist.size()-1);
            }
        }
    }

其中

addlist为临时存储的集合，begin为从数组开始的位置，needNum为每个小数组拆分几个元素为一组，上面的例子中就为3，strings为源数组，result为拆分后存储的结果集