LeetCode刷题记69

47. 全排列 II

题目

class Solution {
    public void F(List<List<Integer>> ans, int[] nums, int cur, Set<List<Integer>> set) {
        if (cur == nums.length) {
            List<Integer> tmp = new ArrayList<Integer>();
            for (int num : nums) {
                tmp.add(num);
            }
            if (set.contains(tmp) == false) {
                set.add(tmp);
                ans.add(tmp);
            }
            return;
        }
        for (int i = cur; i < nums.length; i ++) {
            if (i != cur && nums[i] == nums[cur]) continue;
            int tmp = nums[cur];
            nums[cur] = nums[i];
            nums[i] = tmp;
            F(ans, nums, cur + 1, set);
            nums[i] = nums[cur];
            nums[cur] = tmp;
        }
    }
    public List<List<Integer>> permuteUnique(int[] nums) {
        List<List<Integer>> ans = new ArrayList();
        F(ans, nums, 0, new HashSet<List<Integer>>());
        return ans;
    }
}

1/5
69/150