add new solutions

solutions/2/q228/solution.go

@@ -0,0 +1,32 @@
+package q228
+
+import (
+	"fmt"
+	"strconv"
+)
+
+func addToRanges(output []string, a, b int) []string {
+	if a == b {
+		return append(output, strconv.FormatInt(int64(a), 10))
+	}
+	return append(output, fmt.Sprintf("%d->%d", a, b))
+}
+
+func summaryRanges(nums []int) []string {
+	if len(nums) == 0 {
+		return nil
+	}
+
+	output := []string{}
+	l := 0
+	for r := 1; r < len(nums); r++ {
+		if nums[r]-nums[r-1] != 1 {
+			output = addToRanges(output, nums[l], nums[r-1])
+			l = r
+		}
+	}
+	output = addToRanges(output, nums[l], nums[len(nums)-1])
+	return output
+}
+
+var _ = summaryRanges