Merge pull request neetcode-gh#2065 from josuebrunel/feat/0047-permutations-ii.go

Create 0047-permutations-ii.go

Author: tahsintunan

go/0047-permutations-ii.go

@@ -0,0 +1,33 @@
+func permuteUnique(nums []int) [][]int {
+	numLen := len(nums)
+	res := [][]int{}
+	counter := make(map[int]int)
+
+	for _, n := range nums {
+		counter[n]++
+	}
+
+	var backtrack func([]int, map[int]int)
+
+	backtrack = func(perm []int, counter map[int]int) {
+		if len(perm) == numLen {
+			res = append(res, append([]int{}, perm...))
+			return
+		}
+
+		for n, count := range counter {
+			if count == 0 {
+				continue
+			}
+			perm = append(perm, n)
+			counter[n]--
+			backtrack(perm, counter)
+			perm = perm[:len(perm)-1]
+			counter[n]++
+		}
+	}
+
+	backtrack([]int{}, counter)
+
+	return res
+}