add new solutions

solutions/1/q128/solution.go

@@ -0,0 +1,27 @@
+package q128
+
+func longestConsecutive(nums []int) int {
+	set := make(map[int]struct{}, len(nums))
+	for _, n := range nums {
+		set[n] = struct{}{}
+	}
+
+	longest := 0
+	for n := range set {
+		if _, ok := set[n-1]; ok {
+			continue
+		}
+		r := n
+		for {
+			if _, ok := set[r+1]; ok {
+				r++
+			} else {
+				break
+			}
+		}
+		longest = max(longest, r-n+1)
+	}
+	return longest
+}
+
+var _ = longestConsecutive