Basic CP Resources

Getting Started:

Programming Language:

To get start with competitive programming you must be comfortable with at least one programming language. We prefer C++ because it’s more beginner’s friendly and also more useful for programming contests. Here are few topics you must learn before you start programming contest.

Input/Output
Data types
Loop/Nested Loop
If else
Functions
Structure
String processing

Checkout this websites for resource on C++:

Create an account in vjudge:

https://vjudge.net/

Try this easy problems to get used to problem solving:

Comments

Big O Notation — Time & Space Complexity in Ruby!

Big O Cheat Sheet In this post, we will look at the Big O Notation both time and space complexity! For all our examples we will be using Ruby. What is Big O Notation? Big O notation is just a fancy way of describing how your code’s performance depends on the amount of data its processing. It allows us to calculate the worst possible runtime of an algorithm, or how long it takes the algorithm to complete. In other words, it informs us of how much it will slow down based on the input size. It’s usually talked about in two ways the time complexity ( how long an algorithm takes )and space complexity ( how much space an algorithm uses ) Let me put this graph here we can refer to it as we go on, it’s a graph showing the complexities compare against each other. Big O complexity chart Time Complexity Before we get try wrapping our heads around the different big O notations here is a nice table that I am borrowing to show how speed will slow down based on the size of the datas...

NT Part 2: Generating Primes, Prime Test, Prime Factorization

Generating primes fast is very important in some problems. Let's cut to the chase and introduce Eratosthenes's Sieve. The main idea is the following. Suppose we want to find all primes between 2 and 50. Iterate from 2 to 50. We start with 2. Since it is not checked, it is a prime number. Now check all numbers that are multiple of except 2. Now we move on, to number 3. It's not checked, so it is a prime number. Now check all numbers that are multiple of , except 3. Now move on to 4. We see that this is checked - this is a multiple of 2! So 4 is not a prime. We continue doing this. Here's the implementation. #include <stdio.h> int primechk [ 21000 ] ; void preprocess ( void ) { int i, j ; for ( i = 2 ; i <= 20000 ; i ++ ) { primechk [ i ] = 1 ; } for ( i = 2 ; i <= 20000 ; i ++ ) { if ( primechk [ i ] == 1 ) { for ( j = 2 ; i * j <= 20000...

NT Part 6: Sieve of Eratosthenes(Details)

About 2300 years ago from today, famous Greek mathematician Euclid proved that there are an infinite number of prime numbers. Since then people have been searching for these prime numbers. In 1849, one of the greatest mathematician of all time, Carl Fredrick Gauss, had identified almost all of the prime numbers within the first 3 hundred thousand whole numbers. In the age of computers, we can find large prime numbers in the blink of an eye. But to do that, we need to know a bit of programming and a 2000 year old algorithm. By the end of this tutorial, you will be able to figure out a solution on your own to Gauss’s problem. What is a Prime Number? A prime number is an integer number that is divisible by 1 and the number itself only. For example, 7 is divisible by 1 and 7 only. But 6 is not a prime number because 6 is be divisible by 2 and 3 as well. It is worth mentioning that 1 itself is not a prime number. Now if you are asked to determine if a number is a prime number, you can...

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