go: add «78. Subsets»

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

go/subsets.go

@@ -0,0 +1,29 @@
+package subsets
+
+func subsets(nums []int) [][]int {
+	var sets [][]int
+
+	var subsetsRec func(int)
+
+	var runningSet []int
+	subsetsRec = func(i int) {
+		if i == len(nums) {
+			toAppend := make([]int, len(runningSet))
+			copy(toAppend, runningSet)
+
+			sets = append(sets, toAppend)
+			return
+		}
+
+		// Skip the current element
+		subsetsRec(i + 1)
+
+		// Include the current element
+		runningSet = append(runningSet, nums[i])
+		subsetsRec(i + 1)
+		runningSet = runningSet[:len(runningSet)-1]
+	}
+
+	subsetsRec(0)
+	return sets
+}