go: add «2597. The Number of Beautiful Subsets»

Signed-off-by: Matej Focko <me@mfocko.xyz>

go/the-number-of-beautiful-subsets.go

@@ -0,0 +1,32 @@
+package the_number_of_beautiful_subsets
+
+import (
+	"slices"
+)
+
+func beautifulSubsets(nums []int, k int) int {
+	seen := make(map[int]int)
+
+	var dfs func(int, int) int
+	dfs = func(lastNum, i int) int {
+		// BASE: Got to the end of the slice
+		if i >= len(nums) {
+			return 1
+		}
+
+		// Initialize with skipping the current number
+		foundSubsets := dfs(lastNum, i+1)
+
+		// Check if we can include the current number
+		if seen[nums[i]-k] == 0 && seen[nums[i]+k] == 0 {
+			seen[nums[i]] += 1
+			foundSubsets += dfs(nums[i], i+1)
+			seen[nums[i]] -= 1
+		}
+
+		return foundSubsets
+	}
+
+	slices.Sort(nums)
+	return dfs(nums[0]-k-1, 0) - 1
+}