Given a non-empty 2D array grid of 0s and 1s, an island is a group of 1s (representing land) connected 4-directionally (horizontal or vertical.) You may assume all four edges of the grid are surrounded by water. Count the number of distinct islands. An island is considered to be the same as another if and only if one island can be translated (and not rotated or reflected) to equal the other. Examp...
1.失败，使用TransportClientpublicstaticvoid bulkInsert(TransportClient client) throws IOException {List<Person> ps=new ArrayList<Person>();Person one=new Person();one.setId("1");one.setAddress("add");one.setMobile("1111");one.setSex("f");one.setUsername("www");ps.add(one);Person two=new Person();two.setId("2");two.setAddress("add");two.setMobile("2222");two.setSex("f");two.setUsername("www");ps.ad...
类似筛素数的方法……求出前缀和。然后直接O(1)回答即可。 1 #include <bits/stdc++.h>2 3usingnamespace std;4 5#define rep(i,a,b) for(int i(a); i <= (b); ++i)6 7constint N = 10000000 + 10;8 9int num[N]; 10bool p[N]; 11int T, n, m; 1213int main(){ 1415 memset(p, true, sizeof p); 16 memset(num, 0, sizeof num); 1718 p[1] = false; 19 rep(i, 2, N - 6) if (p[i]...
You have a graph of n nodes. You are given an integer n and an array edges where edges[i] = [ai, bi] indicates that there is an edge between ai and bi in the graph. Return the number of connected components in the graph. Example 1:Input: n = 5, edges = [[0,1],[1,2],[3,4]] Output: 2Example 2:Input: n = 5, edges = [[0,1],[1,2],[2,3],[3,4]] Output: 1 1 class Solution {2 public int countComponen...
DescriptionBZOJ3275有一些数，你需要选出一些，使得他们之中，任意两个数\(a,b\)都不满足\(\exists c,a^2+b^2=c^2\land\gcd(a,b)=1\)。Solution这又是一道很具有启发性的题。观察性质我们发现，偶数和偶数不可能冲突，而存在奇偶之间冲突的情况，那么，奇数之间是否会冲突呢？因为\((2n+1)^2\bmod 4=1，(2n)^2\bmod 4 =0\)，但是\(a^2+b^2\bmod 4=2\)，所以两个奇数不会冲突。然后？这就是一个二分图，跑个最大独立集就好了。Code...
题目描述：Given a digit string, return all possible letter combinations that the number could represent.解题分析：回溯法的典型应用，用一个数据结构表示出按键与其表示字母的对应关系，直接用回溯法做即可。具体代码： 1publicclass Solution {2privatestatic List<String> results=new ArrayList<String>();3privatestatic String[] array= {"","","abc","def","ghi","jkl","mno","pqrs","tuv","wxyz"};4publicstatic Lis...
ORA-03113: end-of-file on communication channelProcess ID: 3880Session ID: 125 Serial number: 3 2.想看下数据库的状态，发现提示：not connected to ORACLESYS@EMREP> select status,instance_name from v$instance;ERROR:ORA-03114: not connected to ORACLE 3.排查错误，使用Oracle三部启动法： startup nomount；（如果起来，说明参数文件没问题） alter database mount；（如果起来，说明控制文件没问题） alter databas...
窗口函数 row number + partition by 排序 数据排序后再取第一个值 select * from (select *, Row_Number() over (partition by uid order by created_at ) rank from ods_lps_kkb_cloud_edu.student_homework_record wherehomework_id=37)rank=1