By studying fossil records, scientists recognized that many animal phyla started appearing into existence about 541 million years ago (Cambrian period). During this time, life on Earth probably went through rapid evolution as all the major animal groups suddenly appeared. Scientists called this period as “Cambrian explosion”.

Why did many…

# Merge Sort

Today, I will describe a new sorting algorithm: Merge Sort, a divide-and-conquer algorithm invented by John von Neumann in 1945. The general idea of merge sort is: when you solve a problem, if you can split the problem into two halves, solve each of them, one at a time (which…

# The “Power” of Shell Sort

Hi guys! In this blog, I’m going to explain to you about the “Power” of Shell Sort. Enjoy!

As you guys know, Donald L. Shell “gave birth” to the Shell Sort algorithm. He made substantial improvements to the insertion sort algorithm. This modified version is now called Shell sort. The…

# List Comprehension in Python

Python is known for allowing you to write code that’s simple, easy to write, and almost as easy to read as plain English. One of Python’s most remarkable features is the list comprehension.

# What is List Comprehension?

List comprehension is a way of making list but in a single, short line. Yet, many developers…

# For Loops: How To Tell if a Number is Prime or Not in Python

So far, I have only used while loops to determine if a number is prime or not. For today, I am going to explain to you how you can use for loop to tell if a number is prime or not.

To understand the code below, you first need to…

# The Faster Version — How To Tell if a Number is Prime or not in python

In my last blog, I showed you the slower version of how to tell if a number is prime or not. Last time, I promised you that I’d show you the faster version in my next blog.

So, here it is:

`x = 17i = 0length = len(the_primes)the_primes = [2,3,5,7,11,13]is_prime = Truewhile i < length:    if x % the_primes[i] == 0:        is_prime = False        break    i = i + 1if is_prime == True:    print((f'{x} is a prime number!')) else:    print((f'{x} is not a prime number'))`

Input: x = 17

Output: 17 is a prime number!

I found out that you really don’t have to divide it by all the numbers before the number. You only have to divide it by the prime numbers before it.

# Prime Numbers

A prime number is a number greater than 1 that is not a product of two smaller natural numbers. For example, 3 is prime because the only ways of writing it as a product, 1 × 3 or 3 × 1, involve 3 itself. But 6 isn’t a prime number… ## Ann

Hi! I'm an elementary school student.