add new solutions

solutions/1/q199/solution.go

@@ -0,0 +1,37 @@
+package q199
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+func rightSideView(root *TreeNode) []int {
+	ret := []int{}
+
+	type qElem struct {
+		height int
+		node   *TreeNode
+	}
+
+	queue := []qElem{{0, root}}
+	var last *qElem
+	for ; len(queue) > 0; queue = queue[1:] {
+		cur := &queue[0]
+		if cur.node == nil {
+			continue
+		}
+		if last != nil && last.height < cur.height {
+			ret = append(ret, last.node.Val)
+		}
+		last = cur
+		queue = append(queue, qElem{cur.height + 1, cur.node.Left}, qElem{cur.height + 1, cur.node.Right})
+	}
+	if last != nil {
+		ret = append(ret, last.node.Val)
+	}
+
+	return ret
+}
+
+var _ = rightSideView