Hey guys can you help with this basic programming algorithm?

Question

Develop an algorithm to print all prime numbers between 1 and N. Where N is an integer value less than or equal to 1000. You can use either pseudo code or flow chart.

Attempt:

START
Get N
If 1 >= N > 1000
Print False
For i=2, i<N, i++
If N%i==0
Print False
For i=2, i<=N, i++
If i is Prime
Print i
END

Answer 1

The concept looks like as follows:
isPrime= true;
for(int i=2;i<=num/2;i++)
{
temp=num%i;
if(temp==0)
{
isPrime=false;
break;
}
}

Answer 2

I did some rewrite of your algorithm, say if I correctly guess your though (because that's not obvious^^):

START
Get N
If 1 >= N > 1000
Print False
endIf
For i=2, i<N, i++
If N%i==0
Print False
endIf
endFor
For i=2, i<=N, i++
If i is Prime
Print i
endIf
endFor
END

Anyway, why these "print false" ?

And your task is to "print all prime numbers between 1 and N", isn't it?
Are you sure that you don't have to explicit the "is Prime"?

Because if so, for what I understand, it's enough to do:

START
GET N
FOR (X=1; X<=N; ++X)
IF X IS PRIME
PRINT X
END IF
END FOR
END

That seems to me very too much simple to be what's expected ;P

Answer 3

Kiibo Ghayal Ok i appreciate that..i have solved some related problems. But this one is a bit difficult.
I will try and come up with what something.

Answer 4

Michael Gidey algortithm is algorithm, by essence it doesn't involve high nor low level programming language ^^

... buy don't care: you make me laugh, and I was just sharing that... I can understand ;)

Where do you stuck exactly?
At the prime numbers generation or at the formating of the result?

Answer 5

Are you really sure that you need to write the "algorithm" of just iterating plus checking the user entry rather than the one to determine if a number is prime?

I intentionally I not done user entry check, as that seems to me not an "algorithm" task... but if you want:

START
GET N
IF N%1 OR N<1 OR N>1000
ERROR
END IF
...

Michael Gidey who give you or where did you find this exercise? :o

[edited]
it seems as much obvious, that I forgotten the greater than 1000 case :P

Answer 6

Michael Gidey :D

You've titled your question with "basic programming algorithm", and finally you qualify it as "a bit difficult" ;P

Answer 7

What i meant by basic is, we are supposed to use pseudo code or flow chart only. Not high level programing language.

Answer 8

𝐊𝐢𝐢𝐛𝐨 𝐆𝐡𝐚𝐲𝐚𝐥
can you review my answer to the above question?

START
Get N
If 1 >= N > 1000
Print False
For i=2, i<N, i++
If N%i==0
Print False
For i=2, i<=N, i++
If i is Prime
Print i
END

Answer 9

Thanks Visph, i think you r right.
But N should be an integer b/n 1 and 1000....shouldn't you specify that?

Answer 10

Its a class assignment...im a 1st year student of computer science

Answer 11

Could you copy-paste the EXACT words of the assignement, please?

I really doubt that your task should limit to that ^^

Answer 12

It is the exact question i posted here. Word by word

Answer 13

And who did tell you that you doesn't need to explicit the "is prime" part?

Answer 14

Develop an algorithm to print all prime numbers between 1 and N. Where N is an integer value less than or equal to 1000. You can use either pseudo code or flow chart.

Answer 15

It could be something like this.
1. Define variable n
2. Define array that contains 2, 3 and 5.
3. Define residue
4. Define a for with an index, that goes from 1 to 1000.
>Inside for
5. Set the value of the index to the n variable
6. Define a second for with an index with a size for the index of the array length -1.
>Inside for
7. Set the value of the division of the n variable with the array value indicate by the index position to the residue variable.
8. Define an if that compares the residue result module with one
9. If is true, then print n
I dont remember how this should be write. I hope it helps you.

Answer 16

Tnx David