# Blog

## Project Euler problem 4 T-SQL

Posted by on 22:47 in code | 2 comments

Project Euler problem 4 was easier then 3. A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91*99 Find the largest palindrome made from the product of two 3-digit numbers. 1 2 3 4 5 6 7 8 9 10 11 12 13 USE tempdb WITH Scheherazade (i) AS ( SELECT TOP 600 ROW_NUMBER()OVER(ORDER BY object_id)+399 FROM sys.all_objects ) SELECT TOP 11 a.i,b.i , a.i*b.i AS j FROM Scheherazade a CROSS JOIN Scheherazade b WHERE...

## Project Euler problem 3 T-SQL Find Prime factors

Posted by on 11:15 in code | 6 comments

Project Euler Problem 3 is: The prime factors of 13195 are 5, 7, 13 and 29. What is the largest prime factor of the number 600851475143 ? I thought of finding prime numbers and try to divide the number 600851475143 with them and then check if I found all the factors and finding the biggest one. For finding primes quickly under 10 millions Sieve of Eratosthenes is wellknown algorithm that has been around for 2500 years. ( What I do not understand of the algorithm is that I only have to check up to the square root of the number serie see row...

## Sorting Chinese Characters in Javascript

Posted by on 13:44 in code | 4 comments

To start learning to write a plug-in for jQuery component Datatables  I have made a webpage  http://sorting.lcube.se/. You can try to sort on different terms there. I plan to explain how Chinese characters are sorted and tell how I make the sorting and what troubles i get into. The first problem I had was that i thought  三 (san1) came after 二 (Er4). I was convinced that this was a bug. But after thinking about it I realized that number 3  三 (san1) has the radical 一 which has fewer strokes than the character for two which has two strokes in...

## Sortera kinesiska tecken i javascript

Posted by on 13:21 in code | 1 comment

För att träna på att skriva plug-in till jQuery komponenten Datatables så har jag gjort en websida: http://sorting.lcube.se/ . Där kan man prova sortera på olika begrepp med min plug-in. Jag tänker förklara hur jag förstått hur kinesiska tecken sorteras samt utveckla hur jag gör  och vilka bekymmer som uppstår. Det första problemet jag hade var att jag trodde att 三 (san1) kom efter 二 (Er4). Det här måste vara en bugg var min första reflektion. Men efter att ha sovit på saken så insåg jag att  talet 3  三 (san1) har ju radikalen 一 vilket har...

## Project Euler problem 2 T-SQL

Posted by on 14:08 in code | 5 comments

Euler problem 2: By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms. This is a sort of running sum problem that used to be hard (before T-SQL in SQL server 2012) I solved it with known math formula and recursion with common table expression. Tomas as usual solved with single-statement magic. Fibonacci can formula can be calculated by using golden ratio with Binets formula. (cool) . I define a function to calculate Fibonacci for the term n as: golden ratio raised to...

## Project Euler with T-SQL

Posted by on 13:15 in code | 2 comments

Me and colleague in my current Project Tomas Eriksson  decided to start to try the Project Euler problemes in Microsoft SQL Servers  Language Transact SQL (T-SQL). First problem was: Add all the natural numbers below one thousand that are multiples of 3 or 5. I made my solution hack back in 2008. It has some flaws. But I post it here to invite criticism. ( Yes I know I should have used % for mod instead of floor, yes I know while loops in SQL do not earn respect) — Euler 1. Add all the natural numbers below one thousand that are...