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LeetCode 33 仅旋转一次，数字之间不相等class Solution { public int search(int[] arr, int target) { int left = 0; int right = arr.length - 1; while (left <= right) { int mid = (left + right) / 2; if (arr[mid] == t

非递归前序遍历class Solution { public List<Integer> preorderTraversal(TreeNode root) { List<Integer> res = new ArrayList<Integer>(); if (root == null) { return res; } Deque<TreeNode> stac