题目如下: Write a query identifying the type of each record in the TRIANGLES table using its three side lengths. Output one of the following statements for each record in the table: Equilateral: It's a triangle with  sides of equal length. Isosceles: It'…

[LeetCode]Pascal's Triangle II 解题报告 标签(空格分隔): LeetCode 题目地址:https://leetcode.com/problems/pascals-triangle-ii/description/ 题目描述: Given an index k, return the kth row of the Pascal's triangle. For example, given k = 3, Return [1,3,3,1]. Note: Could yo…

Given numRows, generate the first numRows of Pascal's triangle. For example, given numRows = 5,Return [ [1], [1,1], [1,2,1], [1,3,3,1], [1,4,6,4,1] ] 解题思路1:迭代插入(未通过) [ [ [ [ [1], [1], [1], [1], [1], [1,1], [1,1], [1,1] [1], ==> [1,2], ==> [1,2,1], =…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/valid-triangle-number/description/ 题目描述: Given an array consists of non-negative integers, your task is to count the number of triplets chosen from the array t…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 三重循环 组合函数 日期 题目地址:https://leetcode.com/problems/largest-triangle-area/description/ 题目描述 You have a list of points in the plane. Return the area of the largest triangle that can…

题目简述: Given an index k, return the kth row of the Pascal's triangle. For example, given k = 3, Return [1,3,3,1]. Note: Could you optimize your algorithm to use only O(k) extra space? 解题思路: 这里的关键是空间的使用,既然只能用O(K)很容易就想到我们要进行回卷(名字好像不对).我的做法是每一次都在后面新加入一个数…

题目简述: Given numRows, generate the first numRows of Pascal's triangle. For example, given numRows = 5, Return [ [1], [1,1], [1,2,1], [1,3,3,1], [1,4,6,4,1]] 解题思路: 很简单的问题,只要把两头的一拿出来,中间就是两个数相加了. class Solution: # @return a list of lists of integers def…

Given numRows, generate the first numRows of Pascal's triangle. For example, given numRows = 5,Return [ [1], [1,1], [1,2,1], [1,3,3,1], [1,4,6,4,1] ] 思路:杨辉三角,直接按规律生成即可 vector<vector<int> > generate(int numRows) { vector<vector<int>>…

>>> a=520 >>> type(a) <class 'int'> >>> a=' >>> type(a) <class 'str'> >>> a=5.2 >>> type(a) <class 'float'> >>> a=True >>> type(a) <class 'bool'> >>>…

https://www.hackerrank.com/challenges/how-many-substrings/problem 题解 似乎是被毒瘤澜澜放弃做T3的一道题(因为ASDFZ有很多人做过,当然,他换了一道更毒瘤的--) 仓鼠在最后一天的时候提了一嘴然后我发现依旧菜菜的不会--(因为太菜模拟天天被吊打) 仓鼠好神仙啊%%%(烤熟了味道怎么样啊) 这道题三个数据结构结合在一起使用,但是感觉却没有那么码农,就是直接把板子套一套(当然板子不熟另当别论),用namespace的话可以降低编码…

Given an index k, return the kth row of the Pascal's triangle. For example, given k = 3, Return [1,3,3,1]. Note: Could you optimize your algorithm to use only O(k) extra space? 注意:只开辟O(K)的内存空间,所以只保存前一组数列和当前数组,并不断滚动更新即可. class Solution { public: vecto…

Given an index k, return the kth row of the Pascal's triangle. For example, given k = 3,Return [1,3,3,1]. Note:Could you optimize your algorithm to use only O(k) extra space? 解题思路1(实现巧妙,但时间复杂度高): 空间复杂度O(k),时间复杂度O(k^2) 和Pascal's Triangle类似,每一行数列,从后往前找…

题目链接:Running Time of Quicksort Challenge In practice, how much faster is Quicksort (in-place) than Insertion Sort? Compare the running time of the two algorithms by counting how many swaps or shifts each one takes to sort an array, and output the dif…

 Calvin is driving his favorite vehicle on the 101 freeway. He notices that the check engine light of his vehicle is on, and he wants to service it immediately to avoid any risks. Luckily, a service lane runs parallel to the highway. The length of th…

problem 812. Largest Triangle Area solution: class Solution { public: double largestTriangleArea(vector<vector<int>>& points) { double res = 0.0; , y1=, x2=, y2=, x3=, y3=; ; i<points.size(); ++i) { ; j<points.size(); ++j) { ; k<p…

Candy Replenishing Robot Find the Minimum Number 直接模拟 Melodious password dfs输出方案 Poles 题意:有多个仓库,只能从后面的仓库运动前面的仓库,现在要把仓库合并成k个,移动一个仓库i到另个仓库j的代价是costi*(xi-xj),问最小代价. 解一下就会发现是个斜率优化,做k次就可以了 #include<cstdio> #include<cstring> #include<algorithm>…

在jxzz上发现的一个做题网站,每周都有训练题,题目质量……前三题比较水,后面好神啊,而且类型差不多,这周似乎是计数专题…… Army Game 然后给出n*m,问需要多少个小红点能全部占领 解法:乘法... Best Divisor 给一个数,问一个数的约数中数字和最大的约数. 解法:直接分解质因数就可以啦. Twins 孪生质数定义为两个质数之差为2,问n,m之间有多少个孪生质数(n<=m<=10^9,m-n<=10^6) 解法:显然直接判断区间内相邻的两个奇数是否为质数就可以啦.然…

题目链接:Median 做了整整一天T_T 尝试了各种方法: 首先看了解答,可以用multiset,但是发现java不支持: 然后想起来用堆,这个基本思想其实很巧妙的,就是维护一个最大堆和最小堆,最大堆存放前半部分较小的元素,最小堆存放后半部分较大的元素,并且最大堆的所有元素小于最小堆的所有元素:保持最大堆最多比最小堆多一个元素.每次插入元素的时候都先插入到最大堆,如果发现最大堆比最小堆多了两个个,那么就从最大堆里面拿出最大的放到最小堆里面:如果发现最大堆里面新插入的元素破坏了最大堆所有元素小于…

题目链接:Coin on the Table 一开始想用DFS做的,做了好久都超时. 看了题解才明白要用动态规划. 设置一个三维数组dp,其中dp[i][j][k]表示在时间k到达(i,j)所需要做的最小改动,那么递推式如下: 图片来源:Editorial,其中当从周围的格子可以直接移动到(i,j)时,delta=0:否则,需要改变周围格子的方向符号,delta=1. 即k-1时刻在(i,.j)周围的四个格子,然后在k时刻移动到(i,j).并且,看这四个格子中的方向符号是否直接可以完成这次移动,…

题目链接:Pairs 完全就是Two Sum问题的变形!Two Sum问题是要求数组中和正好等于K的两个数,这个是求数组中两个数的差正好等于K的两个数.总结其实就是“骑驴找马”的问题:即当前遍历ar[i],那么只要看数组中是否存在ar[i]+K或者ar[i]-K就可以了,还是用HashMap在O(1)的时间完成这个操作. 题目有一点没说清楚的就是元素是否有重复,从Editorial来看似乎是没有重复,不过我还是用map的value记录了数出现的频率来处理了重复. 代码如下: import jav…

题目链接:Cut the tree 题解:题目要求求一条边,去掉这条边后得到的两棵树的节点和差的绝对值最小. 暴力求解会超时. 如果我们可以求出以每个节点为根的子树的节点之和,那么当我们去掉一条边(a,b)的时候,其中的一棵树必是以a或者b为根的子树,那么我们就可以知道生成的两棵树的节点之和了.所以,当我们得到以每个节点为根的子树节点和这个信息后(把这个信息存储在TreeNode的value变量中),通过遍历每个节点(每个节点为根的子树必然为某次cut得到的子树之一,例如下图中,2为根的子树对应…

Numeros, The Artist, had two lists A and B, such that, B was a permutation of A. Numeros was very proud of these lists. Unfortunately, while transporting them from one exhibition to another, some numbers from List A got left out. Can you find out the…

Sorting is often useful as the first step in many different tasks. The most common task is to make finding things easier, but there are other uses also. Challenge Given a list of unsorted numbers, can you find the numbers that have the smallest absol…

In the Quicksort challenges, you sorted an entire array. Sometimes, you just need specific information about a list of numbers, and doing a full sort would be unnecessary. Can you figure out a way to use your partition code to find the median in an a…

One classic method for composing secret messages is called a square code.  The spaces are removed from the english text and the characters are written into a square (or rectangle). The width and height of the rectangle have the constraint, floor(sqrt…

Sunny and Johnny together have M dollars which they intend to use at the ice cream parlour. Among N flavors available, they have to choose two distinct flavors whose cost equals M. Given a list of cost of N flavors, output the indices of two items wh…

There are N integers in an array A. All but one integer occur in pairs. Your task is to find out the number that occurs only once. Input Format The first line of the input contains an integer N indicating number of integers. The next line contains N …

Insertion Sort is a simple sorting technique which was covered in previous challenges. Sometimes, arrays may be too large for us to wait around for insertion sort to finish. Is there some other way we can calculate the number of times Insertion Sort…

题目连接:Sherlock and MiniMax Watson gives Sherlock an array A1,A2...AN. He asks him to find an integer M between P and Q(both inclusive), such that, min {|Ai-M|, 1 ≤ i ≤ N} is maximised. If there are multiple solutions, print the smallest one. Input For…

题目连接:Game Of Rotation Mark is an undergraduate student and he is interested in rotation. A conveyor belt competition is going on in the town which Mark wants to win. In the competition, there's A conveyor belt which can be represented as a strip of 1…