Merge pull request #54 from fusunx/master

添加 0078.子集.md Javascript

problems/0078.子集.md

@@ -210,7 +210,24 @@ Python：
 
 Go：
 
+Javascript:
 
+```Javascript
+var subsets = function(nums) {
+    let result = []
+    let path = []
+    function backtracking(startIndex) {
+        result.push(path.slice())
+        for(let i = startIndex; i < nums.length; i++) {
+            path.push(nums[i])
+            backtracking(i + 1)
+            path.pop()
+        }
+    }
+    backtracking(0)
+    return result
+};
+```
 
 
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