How to display all prime numbers of N starting at 1 from a given entry?

Question

How to display all prime numbers of N starting at 1 from a given entry?

This is the algorithm I managed to develop so far in portugol:

  programa {
        funcao inicio() {
            inteiro n1, soma ,div,div2

            escreva("digite um numero")
            leia(n1)
            para(inteiro i=1 ;i < n1 ; i++) {
                para(inteiro p =1 ; p < i ;p ++) {
                    div= i/p
                    div2=i-(div*p)

                    se(div2 == 0) {
                        escreva(i,"\n")
                    }
                }
            }  
        }
    }

0

portugol

Author: Naruto senin, 2019-05-12

Source

1 answers

score 0 · Answer 1

Currently on the date of 09/05/19 one user asked the following Question " How to account for the amount of prime numbers in an array?" and I worked out an algorithm for the same in c++ (which was asked in the tag) and I explained to the same some rules of the prime numbers , I will do the same with you, so let's go?

Before developing any algorithm you need to analyze the situation, with this we need to know first next:

What are prime numbers?

A prime number is a natural number greater than 1, whose only positive divisors are 1 and itself . all others are called compound numbers.

What characterizes a prime number ?

Adding the knowledge of the above question, the only even prime number is 2, all others are odd. so with this we know from a general form that the prime numbers are not all odd and by exception the only even number 2.

programa {
    funcao inicio() {
        var n: inteiro

        escreva("digite um número")
        leia(n)

        para(inteiro i = 1 ; i < n ; i++) {
            se((i > 1) e (i % p == 1))
                entao
                    escreva("É NÚMERO PRIMO: ", i)
            fimse
        }  
    }
}