You have a number of envelopes with widths and heights given as a pair of integers (w, h). One envelope can fit into another if and only if both the width and height of one envelope is greater than the width and height of the other envelope. What is…

You have a number of envelopes with widths and heights given as a pair of integers (w, h). One envelope can fit into another if and only if both the width and height of one envelope is greater than the width and height of the other envelope. What is…

https://leetcode.com/problems/russian-doll-envelopes/ You have a number of envelopes with widths and heights given as a pair of integers (w, h). One envelope can fit into another if and only if both the width and height of one envelope is greater tha…

题目描述: You have a number of envelopes with widths and heights given as a pair of integers (w, h). One envelope can fit into another if and only if both the width and height of one envelope is greater than the width and height of the other envelope. Wh…

这个题大意很好理解,通过例子就能明白,很像俄罗斯套娃,大的娃娃套小的娃娃.这个题是大信封套小信封,每个信封都有长和宽,如果A信封的长和宽都要比B信封的要大,那么A信封可以套B信封,现在给定一组信封的大小,要求输出最多有几个信封能套在一起. Example:Given envelopes = [[5,4],[6,4],[6,7],[2,3]], the maximum number of envelopes you can Russian doll is 3 ([2,3] => [5,4] =>…

You have a number of envelopes with widths and heights given as a pair of integers (w, h). One envelope can fit into another if and only if both the width and height of one envelope is greater than the width and height of the other envelope. What is…

You have a number of envelopes with widths and heights given as a pair of integers (w, h). One envelope can fit into another if and only if both the width and height of one envelope is greater than the width and height of the other envelope. What is…

You have a number of envelopes with widths and heights given as a pair of integers (w, h). One envelope can fit into another if and only if both the width and height of one envelope is greater than the width and height of the other envelope.What is t…

You have a number of envelopes with widths and heights given as a pair of integers (w, h). One envelope can fit into another if and only if both the width and height of one envelope is greater than the width and height of the other envelope. What is…

An intuitive DP - should be 'medium'. class Solution { public: int maxEnvelopes(vector<pair<int, int>>& envelopes) { int n = envelopes.size(); ; ) ; // Sort by Area sort(envelopes.begin(), envelopes.end(), [](const pair<int, int> &am…

Leetcode354 暴力的方法是显而易见的 O(n^2)构造一个DAG找最长链即可. 也有办法优化到O(nlogn) 注意 信封的方向是不能转换的. 对第一维从小到大排序,第一维相同第二维从大到小排序. 维护一个符合题意的队列,当队列中的第二维均比当前信封的第二维小时,必然可以增加到队尾. 如果不然,可以让当前信封作为“替补”,它可以在恰当的时候代替恰好比它大的信封. 当替补们足够替换所有已有信封时,就可以增加新的信封了. 比较抽象,不过这个技巧很有趣. 看代码吧,很清晰. class So…

终于将LeetCode的免费题刷完了,真是漫长的第一遍啊,估计很多题都忘的差不多了,这次开个题目汇总贴,并附上每道题目的解题连接,方便之后查阅吧~ 477 Total Hamming Distance 44.10% Meidum 475 Heaters  30.20% Easy 474 Ones and Zeroes  34.90% Meidum 473 Matchsticks to Square  31.80% Medium 472 Concatenated Words 29.20% Hard…

Given an unsorted array of integers, find the length of longest increasing subsequence. For example, Given [10, 9, 2, 5, 3, 7, 101, 18], The longest increasing subsequence is [2, 3, 7, 101], therefore the length is 4. Note that there may be more than…

475. Heaters 思路:每趟循环查找离房子最近的热水器,计算距离,最后取最大距离 public int findRadius(int[] houses, int[] heaters) { Arrays.sort(houses); Arrays.sort(heaters); int j = 0; int res = 0; for(int i = 0; i < houses.length; i++){ //找离house[i]最近的heater while(j < heaters.leng…

尽量抽空刷LeetCode,持续更新 刷题记录在github上面,https://github.com/Zering/LeetCode 2016-09-05 300. Longest Increasing Subsequence 问题:https://leetcode.com/problems/longest-increasing-subsequence/ 分析:http://zering.me/2016/09/02/Longest-Increasing-Subsequence/ 源码:http…

刷题备忘录,for bug-free leetcode 396. Rotate Function 题意: Given an array of integers A and let n to be its length. Assume Bk to be an array obtained by rotating the array A k positions clock-wise, we define a "rotation function" F on A as follow: F(k…

二分查找法作为一种常见的查找方法,将原本是线性时间提升到了对数时间范围,大大缩短了搜索时间,具有很大的应用场景,而在LeetCode中,要运用二分搜索法来解的题目也有很多,但是实际上二分查找法的查找目标有很多种,而且在细节写法也有一些变化.之前有网友留言希望博主能针对二分查找法的具体写法做个总结,博主由于之前一直很忙,一直拖着没写,为了树立博主言出必行的正面形象,不能再无限制的拖下去了,那么今天就来做个了断吧,总结写起来~ (以下内容均为博主自己的总结,并不权威,权当参考,欢迎各位大神们留言讨论…

请点击页面左上角 -> Fork me on Github 或直接访问本项目Github地址:LeetCode Solution by Swift    说明:题目中含有$符号则为付费题目. 如:[Swift]LeetCode156.二叉树的上下颠倒 $ Binary Tree Upside Down 请下拉滚动条查看最新 Weekly Contest!!! Swift LeetCode 目录 | Catalog 序        号 题名Title 难度     Difficulty  两数之…

Binary Search基础 应用于已排序的数据查找其中特定值,是折半查找最常的应用场景.相比线性查找(Linear Search),其时间复杂度减少到O(lgn).算法基本框架如下: //704. Binary Search int search(vector<int>& nums, int target) { //nums为已排序数组 ,j=nums.size()-; while(i<=j){ ; if(nums[mid]==target) return mid; ; ;…

Binary Search 二分法方法总结 code教你做人:二分法核心思想是把一个大的问题拆成若干个小问题,最重要的是去掉一半或者选择一半. 二分法模板: public int BinarySearchTemplate(int[] nums,int target) { if(nums == null || nums.length == 0) return -1; int lo = 0; int hi = nums.length - 1; //A: lo < hi [1,2]找1 找last p…

刷题备忘录,for bug-free 招行面试题--求无序数组最长连续序列的长度,这里连续指的是值连续--间隔为1,并不是数值的位置连续 问题: 给出一个未排序的整数数组,找出最长的连续元素序列的长度. 如: 给出[100, 4, 200, 1, 3, 2], 最长的连续元素序列是[1, 2, 3, 4].返回它的长度:4. 你的算法必须有O(n)的时间复杂度 . 解法: 初始思路 要找连续的元素,第一反应一般是先把数组排序.但悲剧的是题目中明确要求了O(n)的时间复杂度,要做一次排序,是不能达…

［抄题］: 往上走台阶 最长上升子序列问题是在一个无序的给定序列中找到一个尽可能长的由低到高排列的子序列,这种子序列不一定是连续的或者唯一的. 样例 给出 [5,4,1,2,3],LIS 是 [1,2,3],返回 3给出 [4,2,4,5,3,7],LIS 是 [2,4,5,7],返回 4   ［思维问题］: 不知道怎么处理递增:还是坐标型(有小人在里面跳),用i j来进行比较 intialization answer都不止一个点:可以从所有的点开始或结束 ［一句话思路］: ［输入量］:空: 正…

突然很想刷刷题,LeetCode是一个不错的选择,忽略了输入输出,更好的突出了算法,省去了不少时间. dalao们发现了任何错误,或是代码无法通过,或是有更好的解法,或是有任何疑问和建议的话,可以在对应的随笔下面评论区留言,我会及时处理,在此谢过了. 过程或许会很漫长,也很痛苦,慢慢来吧. 编号 题名 过题率 难度 1 Two Sum 0.376 Easy 2 Add Two Numbers 0.285 Medium 3 Longest Substring Without Repeating C…

Russian Doll Envelopes    Largest Divisible Subset     Two Sum - Input array is sorted Russian Doll Envelopes 俄罗斯玩偶嵌套问题,这个是典型的dp问题···强行遍历会提示超时,然而整了好久也没整明白怎么整,网上搜了下 把问题归结为求最长递增子序列问题··然而本人愚钝还是想不明白为啥可以这样做··虽然出来的结果是对的····· 先把数据排序, 用python内建的排序函数进行排序,但是因为…

109. Triangle 此题还可以用DFS,记忆化搜索去做,二刷实现 public class Solution { /** * @param triangle: a list of lists of integers * @return: An integer, minimum path sum */ public int minimumTotal(int[][] triangle) { // write your code here if (triangle == null || tri…

Java Algorithm Problems 程序员的一天 从开始这个Github已经有将近两年时间, 很高兴这个repo可以帮到有需要的人. 我一直认为, 知识本身是无价的, 因此每逢闲暇, 我就会来维护这个repo, 给刷题的朋友们一些我的想法和见解. 下面来简单介绍一下这个repo: README.md: 所有所做过的题目 ReviewPage.md: 所有题目的总结和归纳(不断完善中) KnowledgeHash2.md: 对所做过的知识点的一些笔记 SystemDesign.md:…

删除不常考,面试低频出现题目 删除重复代码题目(例:链表反转206题,代码在234题出现过) 删除过于简单题目(例:100题:Same Tree) 删除题意不同,代码基本相同题目(例:136 & 389,保留一个) 适用人群:有一定刷题基础,算法基础,二刷人群. 建议:400题全部刷完,再精刷这250题. ID Title 1 Two Sum 3 Longest Substring Without Repeating Characters 4 Median of Two Sorted Array…

1. Array 基础 27 Remove Element 26 Remove Duplicates from Sorted Array 80 Remove Duplicates from Sorted Array II 277 Find the Celebrity 189 Rotate Array 41 First Missing Positive 299 Bulls and Cows 134 Gas Station 118 Pascal's Triangle 很少考 119 Pascal's…

先过一下Hard模式的题目吧.   # Title Editorial Acceptance Difficulty Frequency   . 65 Valid Number     12.6% Hard    . 126 Word Ladder II     13.6% Hard    . 149 Max Points on a Line     15.6% Hard    . 146 LRU Cache     16.0% Hard    . 68 Text Justification  …

接上一篇:http://www.cnblogs.com/charlesblc/p/6283064.html 继续过Hard模式的题目吧.   # Title Editorial Acceptance Difficulty Frequency   . 65 Valid Number     12.6% Hard    . 126 Word Ladder II     13.6% Hard    . 149 Max Points on a Line     15.6% Hard    . 146 L…