CODEWITHSUNDEEP
c++for-loop
sphynx
sphynx

Reputation: 413

C++ for loop no output in other way

I've been writting some codes for my practise and now I have a trouble. I need to find divisors of inputted number and output them in file.
Example:
Input: 30
Output: 1 2 3 5 6 10 15 30
This is working pretty well, but answers are like: 30 15 10 6 5 3 2 1 (from other side, but I need from 1 to ...)

#include <fstream>

using namespace std;

int main()
{
    int sk; // number
    ifstream fd ("input.txt");
    ofstream fr ("output.txt");
    fd >> sk;
    for (int i = 1; i < sk++; i++){
        if (sk % i == 0) fr << sk/i << " ";
    }
    fd.close ();
    fr.close ();
}

I've tryed this, but not working, what's the problem? 

#include <fstream>

using namespace std;

int main()
{
    int sk; // number
    ifstream fd ("input.txt");
    ofstream fr ("output.txt");
    fd >> sk;
    for (int i = sk; i < 0; i--){
        if (sk % i == 0) fr << sk/i << " ";
    }
    fd.close ();
    fr.close ();
}

Upvotes: 0

Views: 105

Answers (3)

pposca
pposca

Reputation: 553

If you need the output from 1 to sk, the for loop has to look like here:

#include <fstream>

using namespace std;

int main()
{
    int sk; // number
    ifstream fd ("input.txt");
    ofstream fr ("output.txt");

    fd >> sk;
    for (int i = 1; i <= sk; i++)
        if (sk % i == 0) fr << i << " ";

    fd.close ();
    fr.close ();
}

This will output 1 2 3 5 6 10 15 30

Upvotes: 0

J. Daniel Garcia
J. Daniel Garcia

Reputation: 356

Your loop has the wrong condition:

  for (int i = sk; i < 0; i--){
        if (sk % i == 0) fr << sk/i << " ";
    }

With the condition i<0 it never enters the loop. It should be:

for (int i = sk; i >0 0; i--){
        if (sk % i == 0) fr << sk/i << " ";
    }

Upvotes: 0

Abhishek Bansal
Abhishek Bansal

Reputation: 12715

Instead of outputting sk/i, output just i.

Your i is increasing in ascending order. But you are outputting its counterpart factor 1st. Hence it is getting outputted in decreasing order.

Also, in your second loop, change your termination condition to i >= 1:

for (int i = sk; i >= 1; i--){

Upvotes: 2

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