add new solutions

solutions/13/q1339/solution.go

@@ -0,0 +1,45 @@
+package q1339
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+func sumSumTrees(node *TreeNode) int {
+	if node == nil {
+		return 0
+	}
+	node.Val += sumSumTrees(node.Left) + sumSumTrees(node.Right)
+	return node.Val
+}
+
+func findNearest(node *TreeNode, target int) int {
+	if node == nil {
+		return -1
+	}
+	ret := node.Val
+	l, r := findNearest(node.Left, target), findNearest(node.Right, target)
+	if abs(l-target) < abs(ret-target) {
+		ret = l
+	}
+	if abs(r-target) < abs(ret-target) {
+		ret = r
+	}
+	return ret
+}
+
+func abs(n int) int {
+	if n < 0 {
+		return -n
+	}
+	return n
+}
+
+func maxProduct(root *TreeNode) int {
+	totalSum := sumSumTrees(root)
+	nearest := findNearest(root, totalSum/2)
+	return nearest * (totalSum - nearest) % (1e9 + 7)
+}
+
+var _ = maxProduct