39 lines
1.1 KiB
JavaScript
39 lines
1.1 KiB
JavaScript
/**
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* Definition for a binary tree node.
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* function TreeNode(val, left, right) {
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* this.val = (val===undefined ? 0 : val)
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* this.left = (left===undefined ? null : left)
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* this.right = (right===undefined ? null : right)
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* }
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*/
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/**
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* @param {number[]} nums
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* @return {TreeNode}
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*/
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const sortedArrayToBST = function (nums) {
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};
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function TreeNode(val, left, right) {
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this.val = (val === undefined ? 0 : val);
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this.left = (left === undefined ? null : left);
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this.right = (right === undefined ? null : right);
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}
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/*
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用数组的中间值作为根节点，然后递归的将左半部分和右半部分处理成一颗二叉搜索树，并设置成根节点的左右子树
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*/
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function f1(left, right, nums) {
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// 如果left > right, 说明这个区间没有元素，直接返回null
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if (left > right) return null;
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// 计算中间节点的索引
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const mid = left + Math.floor((right - left) / 2);
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// 创建根节点，或子树的根节点
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const root = new TreeNode(nums[mid]);
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// 递归处理左半部分和右半部分
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root.left = f1(left, mid - 1, nums);
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root.right = f1(mid + 1, right, nums);
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return root;
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}
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