题目链接:https://leetcode-cn.com/problems/convert-sorted-array-to-binary-search-tree/
题目描述
分析
1. 添加到数组中，再排序取值
代码实现
public enum Q108 {
instance;
public TreeNode sortedArrayToBST(int[] nums) {
int l=nums.length;
TreeNode root=new TreeNode(nums[l/2]);
fillNode(nums,root,0,l-1);
return root;
}
public TreeNode sortedArrayToBST1(int[] nums) {
// 左右等分建立左右子树，中间节点作为子树根节点，递归该过程
return nums == null ? null : buildTree(nums, 0, nums.length - 1);
}
private TreeNode buildTree(int[] nums, int l, int r) {
if (l > r) {
return null;
}
int m = l + (r - l) / 2;
TreeNode root = new TreeNode(nums[m]);
root.left = buildTree(nums, l, m - 1);
root.right = buildTree(nums, m + 1, r);
return root;
}
public static void main(String[] args) {
Q108.instance.sortedArrayToBST(new int[]{-10,-3,0,5,9});
}
}
An honest man with ignorance is weak and useless;whereas a learned man with dishonest and fearful. (Britain) Johnson
诚实而无知，是软弱的，无用的；然而有知识而不诚实，那时危险的，可怕的。 – [英] 约翰逊
