Description

Assignment 2
To be handed in via CodeJudge
https://dtu.codejudge.net/02393-e17/assignment
In the following exercises, you will have to compute a function with an input parameter that you should read from cin. The result is to be provided on cout.
Gaussian Sum. Write a program that computes the sum 1 + 2 + … + n for a given positive integer n. For example, for n = 100, the result is 5050.
Another sum. Write a program that computes the sum of all even integers between 0 and n. For instance, for n = 6, the result is 0 + 2 + 4 + 6 = 12.
Prime Factorization. Write a program that computes the prime factorization of a given positive integer. For instance, the factorization of 60 is 2 ∗ 2 ∗ 3 ∗ 5.
Hints:
• In C++, the modulus function % gives the remainder of integer division, i.e., x is divisible by y if and only if x%y == 0.
• Given the number n to factorize, iterate through all the numbers i = 2,3,4,5,… and check whether i divides n. If so, print out “i ∗ ” and continue to check the factorization of n/i. Stop when n cannot be further factorised.
In order to check with CodeJudge, please ensure that (i) the factors are printed in ascending order, (ii) between two factors print a space, an asterisk (∗), and another space, (iii) and at the end there is a newline (see example above).
Approximating π. Compute an approximation of π using Leibniz’ formula:

To that end write a function with header double pi(int n) that computes the first n terms of the infinite summation (and then multiplies by 4). For instance for n = 1 we get the bad approximation 4, and with increasing n, the approximation gets better.