Enumerate All Primes to N

Enumerate All Primes to N

Problem Statement

Write a program that takes an integer argument and returns all primes between 1 and that integer. 

Problem Solving

• There is not much of any solving here as I already know an ancient and well known algorithm for this. It's called the Sieve of Eratosthenes. 
• The idea is to create a list of all numbers to n. 
• Then iterate all number from two and at each number keep marking the multiples of those numbers as false or -1. 
• The iterate to the next non -1 number and do the same. 
• Find Code here. 

Learning

• Must always check for bounds. 
• The time complexity is n2 and space in O(n). 
• There is a way to save some space as the even numbers can be removed. 
• std::iota in the numeric header is a library function that can fill array with increasing numbers.
• There is also a Segmented Sieve which is used for large ranges and by segmenting them into smaller chunks
•  Since I could not understand all aspect of optimizations to this problem I am currently leaving behind this problem and moving on to next one.