@@ -434,6 +434,63 @@ func subsetsWithDup(_ nums: [Int]) -> [[Int]] {
434434}
435435```
436436
437+ ### Scala
438+ 439+ 不使用userd数组:
440+ 441+ ``` scala
442+ object Solution {
443+ import scala .collection .mutable
444+ def subsetsWithDup (nums : Array [Int ]): List [List [Int ]] = {
445+ var result = mutable.ListBuffer [List [Int ]]()
446+ var path = mutable.ListBuffer [Int ]()
447+ var num = nums.sorted // 排序
448+ 449+ def backtracking (startIndex : Int ): Unit = {
450+ result.append(path.toList)
451+ if (startIndex >= num.size){
452+ return
453+ }
454+ for (i <- startIndex until num.size) {
455+ // 同一树层重复的元素不进入回溯
456+ if (! (i > startIndex && num(i) == num(i - 1 ))) {
457+ path.append(num(i))
458+ backtracking(i + 1 )
459+ path.remove(path.size - 1 )
460+ }
461+ }
462+ }
463+ 464+ backtracking(0 )
465+ result.toList
466+ }
467+ }
468+ ```
469+ 470+ 使用Set去重:
471+ ``` scala
472+ object Solution {
473+ import scala .collection .mutable
474+ def subsetsWithDup (nums : Array [Int ]): List [List [Int ]] = {
475+ var result = mutable.Set [List [Int ]]()
476+ var num = nums.sorted
477+ def backtracking (path : mutable.ListBuffer [Int ], startIndex : Int ): Unit = {
478+ if (startIndex == num.length) {
479+ result.add(path.toList)
480+ return
481+ }
482+ path.append(num(startIndex))
483+ backtracking(path, startIndex + 1 ) // 选择
484+ path.remove(path.size - 1 )
485+ backtracking(path, startIndex + 1 ) // 不选择
486+ }
487+ 488+ backtracking(mutable.ListBuffer [Int ](), 0 )
489+ 490+ result.toList
491+ }
492+ }
493+ ```
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439496<div align =" center " ><img src =https://code-thinking.cdn.bcebos.com/pics/01二维码一.jpg width =500 > </img ></div >
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