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