Added 1 JS solution for problem 90

Author: imaginate

javascript/90-Subsets-II.js

@@ -0,0 +1,36 @@
+//////////////////////////////////////////////////////////////////////////////
+// Backtracking
+// Time: O(n*2^n)
+// Space: O(2^n)
+//////////////////////////////////////////////////////////////////////////////
+
+/**
+ * @param {number[]} nums
+ * @return {number[][]}
+ */
+function subsetsWithDup(nums) {
+    
+    nums.sort((a, b) => a - b);
+    const results = [];
+    const result = [];
+    getSubsets();
+    return results;
+    
+    /**
+     * @param {number} start = `0`
+     * @return {void}
+     */
+    function getSubsets(start = 0) {
+        
+        results.push(result.slice());
+        
+        for (let i = start; i < nums.length; ++i) {
+            if (i !== start && nums[i] === nums[i - 1]) {
+                continue;
+            }
+            result.push(nums[i]);
+            getSubsets(i + 1);
+            result.pop();
+        }
+    }
+}