> For the complete documentation index, see [llms.txt](https://leetcode-solution-leetcode-pp.gitbook.io/leetcode-solution/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://leetcode-solution-leetcode-pp.gitbook.io/leetcode-solution/easy.md).

# 第四章 - 高频考题（简单）

这里的题目难度比较小， 大多是模拟题，或者是很容易看出解法的题目，另外简单题目一般使用暴力法都是可以解决的。 这个时候只有看一下数据范围，思考下你的算法复杂度就行了。

当然也不排除很多 hard 题目也可以暴力模拟，大家平时多注意数据范围即可。

以下是我列举的经典题目（带 91 字样的表示出自 **91 天学算法**活动）：

* [面试题 17.12. BiNode](/leetcode-solution/easy/binode-lcci.md)
* [0001. 两数之和](/leetcode-solution/easy/1.two-sum.md)
* [0020. 有效的括号](/leetcode-solution/easy/20.valid-parentheses.md)
* [0021. 合并两个有序链表](/leetcode-solution/easy/21.merge-two-sorted-lists.md)
* [0026. 删除排序数组中的重复项](/leetcode-solution/easy/26.remove-duplicates-from-sorted-array.md)
* [0053. 最大子序和](/leetcode-solution/easy/53.maximum-sum-subarray-cn.md)
* [0066. 加一](/leetcode-solution/easy/66.plus-one.md) 91
* [0088. 合并两个有序数组](/leetcode-solution/easy/88.merge-sorted-array.md)
* [0101. 对称二叉树](/leetcode-solution/easy/101.symmetric-tree.md)
* [0104. 二叉树的最大深度](/leetcode-solution/easy/104.maximum-depth-of-binary-tree.md)
* [0108. 将有序数组转换为二叉搜索树](/leetcode-solution/easy/108.convert-sorted-array-to-binary-search-tree.md)
* [0121. 买卖股票的最佳时机](/leetcode-solution/easy/121.best-time-to-buy-and-sell-stock.md)
* [0122. 买卖股票的最佳时机 II](/leetcode-solution/easy/122.best-time-to-buy-and-sell-stock-ii.md)
* [0125. 验证回文串](/leetcode-solution/easy/125.valid-palindrome.md)
* [0136. 只出现一次的数字](/leetcode-solution/easy/136.single-number.md)
* [0155. 最小栈](/leetcode-solution/easy/155.min-stack.md)
* [0160. 相交链表](/leetcode-solution/easy/160.intersection-of-two-linked-lists.md) 91
* [0167. 两数之和 II 输入有序数组](/leetcode-solution/easy/167.two-sum-ii-input-array-is-sorted.md)
* [0169. 多数元素](/leetcode-solution/easy/169.majority-element.md)
* [0172. 阶乘后的零](/leetcode-solution/easy/172.factorial-trailing-zeroes.md)
* [0190. 颠倒二进制位](/leetcode-solution/easy/190.reverse-bits.md)
* [0191. 位 1 的个数](/leetcode-solution/easy/191.number-of-1-bits.md)
* [0198. 打家劫舍](/leetcode-solution/easy/198.house-robber.md)
* [0203. 移除链表元素](/leetcode-solution/easy/203.remove-linked-list-elements.md)
* [0206. 反转链表](/leetcode-solution/easy/206.reverse-linked-list.md)
* [0219. 存在重复元素 II](/leetcode-solution/easy/219.contains-duplicate-ii.md)
* [0226. 翻转二叉树](/leetcode-solution/easy/226.invert-binary-tree.md)
* [0232. 用栈实现队列](/leetcode-solution/easy/232.implement-queue-using-stacks.md) 91
* [0263. 丑数](/leetcode-solution/easy/263.ugly-number.md)
* [0283. 移动零](/leetcode-solution/easy/283.move-zeroes.md)
* [0342. 4 的幂](/leetcode-solution/easy/342.power-of-four.md)
* [0349. 两个数组的交集](/leetcode-solution/easy/349.intersection-of-two-arrays.md)
* [0371. 两整数之和](/leetcode-solution/easy/371.sum-of-two-integers.md)
* [401. 二进制手表](/leetcode-solution/easy/401.binary-watch.md)
* [0437. 路径总和 III](/leetcode-solution/easy/437.path-sum-iii.md)
* [0455. 分发饼干](/leetcode-solution/easy/455.assigncookies.md)
* [0575. 分糖果](/leetcode-solution/easy/575.distribute-candies.md)
* [821. 字符的最短距离](/leetcode-solution/easy/821.shortest-distance-to-a-character.md) 91
* [0874. 模拟行走机器人](/leetcode-solution/easy/874.walking-robot-simulation.md)
* [1260. 二维网格迁移](/leetcode-solution/easy/1260.shift-2d-grid.md)
* [1332. 删除回文子序列](/leetcode-solution/easy/1332.remove-palindromic-subsequences.md)