Given an integer array, your task is to find all the different possible increasing subsequences of the given array,
and the length of an increasing subsequence should be at least 2 . Example: Input: [4, 6, 7, 7] Output: [[4, 6], [4, 7], [4, 6, 7], [4, 6, 7, 7], [6, 7], [6, 7, 7], [7,7], [4,7,7]] Note: The length of the given array will not exceed 15. The range of integer in the given array is [-100,100]. The given array may contain duplicates,
and two equal integers should also be considered as a special case of increasing sequence.
带重复节点的subset
public List<List<Integer>> findSubsequences(int[] nums) {
List<List<Integer>> ans = new ArrayList<>();
List<Integer> list = new ArrayList<>();
Arrays.sort(nums);
helper(nums, 0, ans, list);
return ans;
}
private void helper(int[] nums, int pos, List<List<Integer>> ans, List<Integer> list) {
if (list.size() >= 2) {
ans.add(new ArrayList(list));
}
for (int i = pos; i < nums.length; i++) {
if (i != pos && nums[i - 1] == nums[i]){
continue;
}
list.add(nums[i]);
helper(nums, i + 1, ans, list);
list.remove(list.size() - 1);
}
}
原文：http://www.cnblogs.com/apanda009/p/7304914.html