duplicate annihilator

In many cases, sorting aims to classify data, which has many duplicate values. Population statistics by age Delete duplicate emails in the email list Sort job seekers by University If you sort repeated data using a normal fast sort, the complexity of N ^ 2 will be caused, but there is no such problem between the merge sort and the three-way fast sort. The comparison between 1/2nlgn and nlgn Three route

1. Querying duplicate Record single fieldsSELECT * from TBL a where exists (select 1 to tbl B where A.username=b.username GROUP by username have count (*) > 1)2. Number of query repetitionsSelect Clistname,count (clistname) from Clalist GROUP by Clistname have Count (*) >13. Delete duplicate records, leaving ROWID minimum recordsDelete from peoplewhere Peopleid in (select Peopleid from People GROUP by Peopl

Method 1: Highlight duplicate data You can highlight repetitive data so you can find them and avoid repetitive entries. The procedure is as follows: First, select the scope of the duplicate data you want to find. For example, if you are looking for duplicates in the employee number, select the "Employee Number" column. Then on the Start tab-> conditional formatting -

[Huawei machine trial exercise questions] 15. Delete duplicate characters/delete duplicate strings, Huawei exercises Question Title: delete duplicate characters. Given a string, remove all redundant characters in the string that have already been duplicated. Keep the remaining characters and output the processed string. Ensure the order in which the characters a

Given a sorted linked list, delete all nodes that has duplicate numbers, leaving only distinct numbers from the Original list.For example,Given1->2->3->3->4->4->5, Return1->2->5.Given1->1->1->2->3, Return2->3.The difference between this and the remove duplicate from sorted list is that, in this case, as long as the node is duplicated, the value of the equal node will be deleted, leaving one in the title doe

Programs that delete duplicate files and programs that delete duplicate files Delete duplicate files Usage: Create a BAT file, such as 1.bat, and write: RemoveDuplicate.exe path1 path2 (or enter the above content under the command line) Where path1 indicates the original folder and path2 indicates the folder to be checked and deleted For example, the folder path1

SQL deletes duplicate and SQL duplicate records in a table. I have encountered the problem of Repeated Records in the table. The fastest way to directly write SQL statements to delete the records is not to copy them to the excel table slowly for manual searching. The following SQL statement finds duplicate records and records with the smallest ID value in Repea

1, avoid the header file repeat containsTEST.H This macro means that if a macro variable is defined Test_h_ it is no longer defined #ifndef test_h_#define test_h_//header file Contents #endifOrTest.h tells the precompiled compiler to include only one #pragma once2. Avoid duplicate definitionsDo not put the function definition in the header file, the correct way is to put the header file function declaration, the source file placement function definiti

Given a string which contains only lowercase letters, remove duplicate letters so this every letter appear once and only O nCE. You must make sure your result are the smallest in lexicographical order among all possible results.Example:Given"bcabc"Return"abc"Given"cbacdcbc"Return"acdb"Credits:Special thanks to @dietpepsi for adding this problem and creating all test cases.This problem allows us to remove duplicate