leetcode Linked List Binary Search Tree

leetcode 109题

Posted by franki on November 11, 2020

有序链表转换二叉搜索树

思路

先把链表的值逐一存入数组

利用二分，把数组的值先确定中位数为root，然后根据root划分左子树、右子树

代码

function sortedListToBST(head) {
    var arr = [];

    while (head) {
        arr.push(head.val);
        head = head.next;
    }

    function buildBST(start, end) {
        if (start > end) return null;
        var mid = start + end >>> 1;
        var root = new TreeNode(arr[mid]);
        root.left = buildBST(start, mid - 1);
        root.right = buildBST(mid + 1, end);
        return root;
    }

    return buildBST(0, arr.length - 1);
}

复杂度分析

  • 时间复杂度：O(nlogn)
  • 空间复杂度：O(n)
CATALOG
    FEATURED TAGS
    前端开发 H5 JavaScript 设计模式 browser jQuery 源码分析 生活 leetcode Array Stack Queue Linked List 剑指offer Binary Search Tree Binary Tree Breadth-First Search Depth-First Search String Set Binary Search Sliding Window Backtracking Dynamic Programming Two Pointers Union Find Sort Bit Operation Recursion Map Graph Search Hash LinkedList QuickSort Trie Design MinHeap Traverse Min Heap Node.js BackEnd SQL MySQL Design Patterns Network 计算机网络 Python
    FRIENDS