如何在数组 JAVA 中存储递归 function 值

Question

I want to store the data variables (String[]) to variable results in ArrayList, and then the final results of recursive function is ArrayList results. in this case return [[ani,budi],[ani,cici],[budi,cici]]. Anyone can help me?

static void combinationUtil(String arr[], String data[], int start,
                                    int end, int index, int r, ArrayList<String[]> results)
        {
            if (index == r){
                results.add(data);
                System.out.println(Arrays.toString(data));
                return;
            }

            for (int i=start; i<=end && end-i+1 >= r-index; i++){
                data[index] = arr[i];
                combinationUtil(arr, data, i+1, end, index+1, r, results);
            }
        }

        public static void main (String[] args) {
            String arr[] = {"ani", "budi", "cici"};
            int r = 2;
            int n = arr.length;
            String data[] = new String[r];
            ArrayList<String[]> results = new ArrayList<String[]>();
            combinationUtil(arr, data, 0, n-1, 0, r, results);
        }

Answer 1

Update the line of adding the array to the list and make a copy, because the saved array is changing in other iterations

results.add(Arrays.copyOf(data, data.length));

, To be like this:

    static void combinationUtil(String arr[], String data[], int start, int end, int index, int r,
            ArrayList<String[]> results) {
        if (index == r) {
            results.add(Arrays.copyOf(data, data.length));
            return;
        }

        for (int i = start; i <= end; i++) {
            data[index] = arr[i];
            combinationUtil(arr, data, i + 1, end, index + 1, r, results);
        }
    }