javajsking
diff --git a/‎.idea/modules.xml
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diff --git a/‎【047】【Permutations II】/src/Solution.java
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+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * @author: wangjunchao(王俊超)
+ * @time: 2018-09-28 15:29
+ **/
+public class Solution {
+
+    public List<List<Integer>> permuteUnique(int[] nums) {
+        List<List<Integer>> res = new ArrayList<>();
+
+        if (nums == null || nums.length == 0){
+            return res;
+        }
+
+        boolean[] used = new boolean[nums.length];
+        List<Integer> list = new ArrayList<>();
+
+        Arrays.sort(nums);
+
+        permuteUnique(nums, used, list, res);
+        return res;
+    }
+
+    private void permuteUnique(int[] nums, boolean[] used, List<Integer> list, List<List<Integer>> res) {
+        if (list.size() == nums.length) {
+            res.add(new ArrayList<>(list));
+            return;
+        }
+
+        for (int i = 0; i < nums.length; i++) {
+            // 第i个数值已经被使用过
+            if (used[i]) {
+                continue;
+            }
+
+            // 第不个字符与前一个字符相等，并且第i-1个字符没有使用，说明此次不应该交换
+            if (i > 0 && nums[i - 1] == nums[i] && !used[i - 1]) {
+                continue;
+            }
+
+            // 标记第i个字符已经被使用
+            used[i] = true;
+            // 添加到临时结果中
+            list.add(nums[i]);
+            // 下一次处理
+            permuteUnique(nums, used, list, res);
+            // 现场还原
+            used[i] = false;
+            list.remove(list.size() - 1);
+        }
+    }
+}