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Here we will see how to generate the Tetranacci numbers using C++. The Tetranacci numbers are similar to the Fibonacci numbers, but here we are generating a term by adding four previous terms. Suppose we want to generate T(n), then the formula will be like below −T(n) = T(n - 1) + T(n - 2) + T(n - 3) + T(n - 4)The first few numbers to start, are {0, 1, 1, 2}Algorithmtetranacci(n): Begin first := 0, second := 1, third := 1, fourth := 2 print first, second, third, fourth for i in range n – ... Read More
For this, you can use GROUP BY HAVING clause. Let us first create a table −mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Value int ); Query OK, 0 rows affected (0.52 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(Value) values(600); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(Value) values(600); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(Value) values(800); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable(Value) values(800); Query OK, 1 row affected (0.09 sec)Display all records from the table ... Read More
For this, use JSON_OBJECTAGG(). Let us first create a table −mysql> create table DemoTable ( Id int, FirstName varchar(100), Age int ); Query OK, 0 rows affected (0.56 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(10, 'John', 23); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values(20, 'Carol', 21); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values(10, 'Sam', 24); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values(20, 'Chris', 20); Query OK, 1 row affected (0.13 sec)Display all records from the ... Read More
In this section we will see how to sort numbers according to their sum of digits. So if a number has lesser sum of digits, then that will be placed at first, then next number will be placed with larger sum of digits.data = {14, 129, 501, 23, 0, 145}after sorting, they will be −data = {0, 14, 23, 501, 145, 129}Here we will create our own comparison logic to sort them. That comparison logic will be used in the sort function in C++ STL.Algorithmcompare(num1, num2): Begin if sum of digits of num1 < sum of digits of num2, ... Read More
In this article, we will learn about the web scraping technique using the Scrappy module available in Python.What is web scraping?Web scraping is used to obtain/get the data from a website with the help of a crawler/scanner. Web scrapping comes handy to extract the data from a web page that doesn't offer the functionality of an API. In python, web scraping can be done by the help of various modules namely Beautiful Soup, Scrappy & lxml.Here we will discuss web scraping using the Scrappy module.For that, we first need to install Scrappy.Type in the terminal or command prompt>>> pip install ... Read More
Let us first create a table −mysql> create table DemoTable ( Logouttime time ); Query OK, 0 rows affected (0.62 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('5:50:00'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values('6:10:10'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('8:00:50'); Query OK, 1 row affected (0.14 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following output −+------------+ | Logouttime | +------------+ | 05:50:00 | | 06:10:10 | | 08:00:50 ... Read More
Here we will see how to sort a list of strings based on their lengths. So if a string has less number of characters, then that will be placed first, then other longer strings will be placed. Suppose the strings arestr_list = {“Hello”, “ABC”, “Programming”, “Length”, “Population”}after sorting, they will be −str_list = {“ABC”, “Hello”, “Length”, “Population”, “Programming”}Here we will create our own comparison logic to sort them. That comparison logic will be used in the sort function in C++ STL.Algorithmcompare(str1, str2): Begin if length of str1 < length of str2, then return 1 return ... Read More
For this, you can use the aggregate function SUM(). Let us first create a table −mysql> create table DemoTable ( isMarried tinyint(1) ); Query OK, 0 rows affected (0.84 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(0); Query OK, 1 row affected (0.26 sec) mysql> insert into DemoTable values(1); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values(1); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable values(0); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable values(1); Query OK, 1 row affected (0.19 sec) mysql> ... Read More
In this section we will see another sorting problem. Suppose we have two arrays A1 and A2. We have to sort A1 in such a way that the relative order among the elements will be same as those are in A2. If some elements are not present in A2, then they will be appended after the sorted elements. Suppose A1 and A2 are the following −A1 = {2, 1, 2, 1, 7, 5, 9, 3, 8, 6, 8} A2 = {2, 1, 8, 3}After the sorting A1 will be like below −A1 = {2, 2, 1, 1, 8, 8, 3, ... Read More
Let’s say you have set dates in the VARCHAR format. Now if you want to update the format, then use the UPDATE command along with STR_TO_DATE(). The syntax is as follows −update yourTableName set yourColumnName=str_to_date(yourColumnName, '%m/%d/%Y');Let us first create a table −mysql> create table DemoTable ( DueDate varchar(100) ); Query OK, 0 rows affected (0.56 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('12/01/2019'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('01/31/2016'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values('03/17/2018'); Query OK, 1 row affected (0.17 ... Read More