Given a 2D board and a word, find if the word exists in the grid. The word can be constructed from letters of sequentially adjacent cell, where "adjacent" cells are those horizontally or vertically neighboring. The same letter cell may not be us…

Validate if a given string is numeric. Some examples: "0" => true " 0.1 " => true "abc" => false "1 a" => false "2e10" => true Note: It is intended for the problem statement to be ambiguous.…

前言 MyBatis是基于“数据库结构不可控”的思想建立的,也就是我们希望数据库遵循第三范式或BCNF,但实际事与愿违,那么结果集映射就是MyBatis为我们提供这种理想与现实间转换的手段了,而resultMap就是结果集映射的配置标签了. 在深入ResultMap标签前,我们需要了解从SQL查询结果集到JavaBean或POJO实体的过程. 从SQL查询结果到领域模型实体 通过JDBC查询得到ResultSet对象 遍历ResultSet对象并将每行数据暂存到HashMap实例中,以结果集的字…

U40620 niiickの还没想好名字的题 给定一个长度为\(n\)的序列\(a_1,a_2...,a_n\) 要求将这\(n\)个数分为\(m\)组,每组可以有任意多个数,但同一组中的数必须是原序列中连续的一段 求如何分组能使得各组的标准差最小, 即求\[min(\sqrt{\sum_{i=1}^m\frac{(x_i-\overline{x})^2}{m}})\]其中\(x_i\)为第\(i\)组数的和,\(\overline{x}\)为各组数和的平均值 求这个最小值 纪念一下交了19遍(…

一.题目说明 题目79. Word Search,给定一个由字符组成的矩阵,从矩阵中查找一个字符串是否存在.可以连续横.纵找.不能重复使用,难度是Medium. 二.我的解答 惭愧,我写了很久总是有问题,就先看正确的写法,下面是回溯法的代码: class Solution { public: int m,n; //左 上 右 下 int dx[4] = {-1,0,1,0}; int dy[4] = {0,1,0,-1}; bool exist(vector<vector<char>&g…

Babelfish Time Limit: 3000MS   Memory Limit: 65536K Total Submissions: 30816   Accepted: 13283 Description You have just moved from Waterloo to a big city. The people here speak an incomprehensible dialect of a foreign language. Fortunately, you have…

What Are You Talking About Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 102400/204800 K (Java/Others)Total Submission(s): 12617    Accepted Submission(s): 4031 Problem Description Ignatius is so lucky that he met a Martian yesterday. But…

统计难题 Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 131070/65535 K (Java/Others)Total Submission(s): 16905    Accepted Submission(s): 7273 Problem Description Ignatius最近遇到一个难题,老师交给他很多单词(只有小写字母组成,不会有重复的单词出现),现在老师要他统计出以某个字符串为前缀的单词数量(单词本身也是自己的前…

Leetcode之回溯法专题-212. 单词搜索 II(Word Search II) 给定一个二维网格 board 和一个字典中的单词列表 words,找出所有同时在二维网格和字典中出现的单词. 单词必须按照字母顺序,通过相邻的单元格内的字母构成,其中“相邻”单元格是那些水平相邻或垂直相邻的单元格.同一个单元格内的字母在一个单词中不允许被重复使用. 示例: 输入: words = ["oath","pea","eat","rain&q…

Leetcode之回溯法专题-79. 单词搜索(Word Search) 给定一个二维网格和一个单词,找出该单词是否存在于网格中. 单词必须按照字母顺序,通过相邻的单元格内的字母构成,其中“相邻”单元格是那些水平相邻或垂直相邻的单元格.同一个单元格内的字母不允许被重复使用. 示例: board = [ ['A','B','C','E'], ['S','F','C','S'], ['A','D','E','E'] ] 给定 word = "ABCCED", 返回 true. 给定 wor…