project euler problem 007

This is a warm-up problem.  Very basic.  Read the discussion thread if your code took more than 0.2 second.

project euler problem 006

sum square difference

please do it in O(1) time;

project euler problem 005

smallest multiple

calculator problem, every one can solve it.

project euler problem 004

largest palindrome product

This problem is simple. We will see other palindromic numbers related problems later.

project euler problem 003

largest prime factor

I use C or C++ to solve project euler problems. But I rarely use long long in coding. After I solved 50 to 100 problems, I found long long is necessity. The problem is easy, even one use some kind of  brute force method. One may read the book from CLRS and try some fancy method. 

It is interesting to notice that for most of the project euler problems that require an integer as an answer, number is usually less than 2^64.  

project euler problem 002

even Fibonacci numbers

around problem 400, there are a lot of problems about Fibonacci numbers. Some on quite difficult to solve. This one is the easiest one that is somewhat related to Fibonacci number.

project euler problem 001

Multiples of 3 and 5

I first started working on project euler in Aug 2011, I really enjoyed solving most of the problems. 

 This is an extremely easy problem, everyone can solve it. No comments needed.