add new solutions

solutions/10/q1022/solution.go

@@ -0,0 +1,29 @@
+package q1022
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+func sum(node *TreeNode, prefix int, ret *int) {
+	if node == nil {
+		return
+	}
+	num := prefix<<1 + node.Val
+
+	if node.Left == nil && node.Right == nil {
+		*ret += num
+	} else {
+		sum(node.Left, num, ret)
+		sum(node.Right, num, ret)
+	}
+}
+
+func sumRootToLeaf(root *TreeNode) int {
+	ret := 0
+	sum(root, 0, &ret)
+	return ret
+}
+
+var _ = sumRootToLeaf