diff --git a/problems/0090.子集II.md b/problems/0090.子集II.md index 03bbd1dc..939ef369 100644 --- a/problems/0090.子集II.md +++ b/problems/0090.子集II.md @@ -310,6 +310,43 @@ class Solution: ``` ### Go +使用used数组 +```Go +var ( + result [][]int + path []int +) + +func subsetsWithDup(nums []int) [][]int { + result = make([][]int, 0) + path = make([]int, 0) + used := make([]bool, len(nums)) + sort.Ints(nums) // 去重需要排序 + backtracing(nums, 0, used) + return result +} + +func backtracing(nums []int, startIndex int, used []bool) { + tmp := make([]int, len(path)) + copy(tmp, path) + result = append(result, tmp) + for i := startIndex; i < len(nums); i++ { + // used[i - 1] == true,说明同一树枝candidates[i - 1]使用过 + // used[i - 1] == false,说明同一树层candidates[i - 1]使用过 + // 而我们要对同一树层使用过的元素进行跳过 + if i > 0 && nums[i] == nums[i-1] && used[i-1] == false { + continue + } + path = append(path, nums[i]) + used[i] = true + backtracing(nums, i + 1, used) + path = path[:len(path)-1] + used[i] = false + } +} +``` + +不使用used数组 ```Go var ( path []int