654. 最大二叉树

Author: hero

leet_code/constructMaximumBinaryTree_test.go

@@ -0,0 +1,40 @@
+package leet_code
+
+import (
+	"testing"
+)
+
+func constructMaximumBinaryTree(nums []int) *TreeNode {
+	return maxTreeNode(nums, 0, len(nums)-1)
+}
+
+func maxTreeNode(num []int, i, j int) *TreeNode {
+	if i > j {
+		return nil
+	}
+	modI := findMaxIndex(num, i, j)
+	root := new(TreeNode)
+	root.Val = num[modI]
+	root.Left = maxTreeNode(num, i, modI-1)
+	root.Right = maxTreeNode(num, modI+1, j)
+	return root
+}
+
+func findMaxIndex(num []int, i, j int) int {
+	var (
+		index    = -1
+		indexNum = -1
+	)
+	for k := i; k <= j; k++ {
+		if indexNum < num[k] {
+			indexNum = num[k]
+			index = k
+		}
+	}
+	return index
+}
+
+func Test_constructMaximumBinaryTree(t *testing.T) {
+	num := []int{3, 2, 1, 6, 0, 5}
+	constructMaximumBinaryTree(num)
+}