全排列(JAVA)

/**
 * 全排列结果集
 */
private List<String> fullPermutationArr;

/**
 * 全排列
 *
 * @param arr
 * @param str
 */
private void fullPermutation(List<Long> arr, String str) {
    Integer cnt = arr.size();
    if (cnt == 1) {
        fullPermutationArr.add(StringUtils.isEmpty(str) ? arr.get(0) + "" : str + "," + arr.get(0));
    } else {
        for (int i = 0; i < arr.size(); i++) {
            Long tmp = arr.get(0);
            arr.set(0, arr.get(i));
            arr.set(i, tmp);
            List<Long> arr2 = new ArrayList<>(arr);
            arr2.remove(0);
            fullPermutation(arr2, StringUtils.isEmpty(str) ? arr.get(0) + "" : str + "," + arr.get(0));
        }
    }
}

// 调用

this.fullPermutationArr= new ArrayList<>();

fullPermutation(yourList, "");

List<String> result = this.fullPermutationArr;