Console Application is not running and shows nothing












-1















The problem is to solve this.



The prime factors of 13195 are 5, 7, 13 and 29.
What is the largest prime factor of the number 600851475143 ?



I wrote this code



#include <iostream>
#include <math.h>
using namespace std;

bool prime(long int a);

int main()
{
long int b = 600851475143/2;
long int k;



for(long int i = 1; i <= b ; i++)
{
if(b % i == 0 && prime(i) == true)
{
k = i;
}
}
cout << k << endl;
return 0;



}

bool prime(long int a)
{
bool p = true;

for(long int i = 2; i <= sqrt(a) && p == true ; i++)
if(a % i == 0) p = false;

return p;
}


and when I execute after a build, it opens a console , and shows nothing










share|improve this question























  • Debuggers are a brilliant tool for solving problems like this. Pop a breakpoint at the start of the program, start up the program, and start start stepping until the program blocks or starts going around in circles.

    – user4581301
    Nov 25 '18 at 21:36











  • g++ spits out warning: overflow in implicit constant conversion [-Woverflow] long int b = 600851475143/2; You should resolve this. Come to think of it, 600851475143/2; is a darn big number. You might want to reconsider using it as a loop bound.

    – user4581301
    Nov 25 '18 at 21:42











  • Regarding the prime computation, this is a brutally slow way to do this. Consider the number of times you are recomputing the i = 2 case.

    – user4581301
    Nov 25 '18 at 21:45











  • I didn't complete the previous thought. Use memoization to reduce the amount of redundant work you have to do. See if you can take advantage of a Prime Number Sieve.

    – user4581301
    Nov 25 '18 at 22:01
















-1















The problem is to solve this.



The prime factors of 13195 are 5, 7, 13 and 29.
What is the largest prime factor of the number 600851475143 ?



I wrote this code



#include <iostream>
#include <math.h>
using namespace std;

bool prime(long int a);

int main()
{
long int b = 600851475143/2;
long int k;



for(long int i = 1; i <= b ; i++)
{
if(b % i == 0 && prime(i) == true)
{
k = i;
}
}
cout << k << endl;
return 0;



}

bool prime(long int a)
{
bool p = true;

for(long int i = 2; i <= sqrt(a) && p == true ; i++)
if(a % i == 0) p = false;

return p;
}


and when I execute after a build, it opens a console , and shows nothing










share|improve this question























  • Debuggers are a brilliant tool for solving problems like this. Pop a breakpoint at the start of the program, start up the program, and start start stepping until the program blocks or starts going around in circles.

    – user4581301
    Nov 25 '18 at 21:36











  • g++ spits out warning: overflow in implicit constant conversion [-Woverflow] long int b = 600851475143/2; You should resolve this. Come to think of it, 600851475143/2; is a darn big number. You might want to reconsider using it as a loop bound.

    – user4581301
    Nov 25 '18 at 21:42











  • Regarding the prime computation, this is a brutally slow way to do this. Consider the number of times you are recomputing the i = 2 case.

    – user4581301
    Nov 25 '18 at 21:45











  • I didn't complete the previous thought. Use memoization to reduce the amount of redundant work you have to do. See if you can take advantage of a Prime Number Sieve.

    – user4581301
    Nov 25 '18 at 22:01














-1












-1








-1








The problem is to solve this.



The prime factors of 13195 are 5, 7, 13 and 29.
What is the largest prime factor of the number 600851475143 ?



I wrote this code



#include <iostream>
#include <math.h>
using namespace std;

bool prime(long int a);

int main()
{
long int b = 600851475143/2;
long int k;



for(long int i = 1; i <= b ; i++)
{
if(b % i == 0 && prime(i) == true)
{
k = i;
}
}
cout << k << endl;
return 0;



}

bool prime(long int a)
{
bool p = true;

for(long int i = 2; i <= sqrt(a) && p == true ; i++)
if(a % i == 0) p = false;

return p;
}


and when I execute after a build, it opens a console , and shows nothing










share|improve this question














The problem is to solve this.



The prime factors of 13195 are 5, 7, 13 and 29.
What is the largest prime factor of the number 600851475143 ?



I wrote this code



#include <iostream>
#include <math.h>
using namespace std;

bool prime(long int a);

int main()
{
long int b = 600851475143/2;
long int k;



for(long int i = 1; i <= b ; i++)
{
if(b % i == 0 && prime(i) == true)
{
k = i;
}
}
cout << k << endl;
return 0;



}

bool prime(long int a)
{
bool p = true;

for(long int i = 2; i <= sqrt(a) && p == true ; i++)
if(a % i == 0) p = false;

return p;
}


and when I execute after a build, it opens a console , and shows nothing







c++ console






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked Nov 25 '18 at 21:31









Mane HambardzumyanMane Hambardzumyan

269




269













  • Debuggers are a brilliant tool for solving problems like this. Pop a breakpoint at the start of the program, start up the program, and start start stepping until the program blocks or starts going around in circles.

    – user4581301
    Nov 25 '18 at 21:36











  • g++ spits out warning: overflow in implicit constant conversion [-Woverflow] long int b = 600851475143/2; You should resolve this. Come to think of it, 600851475143/2; is a darn big number. You might want to reconsider using it as a loop bound.

    – user4581301
    Nov 25 '18 at 21:42











  • Regarding the prime computation, this is a brutally slow way to do this. Consider the number of times you are recomputing the i = 2 case.

    – user4581301
    Nov 25 '18 at 21:45











  • I didn't complete the previous thought. Use memoization to reduce the amount of redundant work you have to do. See if you can take advantage of a Prime Number Sieve.

    – user4581301
    Nov 25 '18 at 22:01



















  • Debuggers are a brilliant tool for solving problems like this. Pop a breakpoint at the start of the program, start up the program, and start start stepping until the program blocks or starts going around in circles.

    – user4581301
    Nov 25 '18 at 21:36











  • g++ spits out warning: overflow in implicit constant conversion [-Woverflow] long int b = 600851475143/2; You should resolve this. Come to think of it, 600851475143/2; is a darn big number. You might want to reconsider using it as a loop bound.

    – user4581301
    Nov 25 '18 at 21:42











  • Regarding the prime computation, this is a brutally slow way to do this. Consider the number of times you are recomputing the i = 2 case.

    – user4581301
    Nov 25 '18 at 21:45











  • I didn't complete the previous thought. Use memoization to reduce the amount of redundant work you have to do. See if you can take advantage of a Prime Number Sieve.

    – user4581301
    Nov 25 '18 at 22:01

















Debuggers are a brilliant tool for solving problems like this. Pop a breakpoint at the start of the program, start up the program, and start start stepping until the program blocks or starts going around in circles.

– user4581301
Nov 25 '18 at 21:36





Debuggers are a brilliant tool for solving problems like this. Pop a breakpoint at the start of the program, start up the program, and start start stepping until the program blocks or starts going around in circles.

– user4581301
Nov 25 '18 at 21:36













g++ spits out warning: overflow in implicit constant conversion [-Woverflow] long int b = 600851475143/2; You should resolve this. Come to think of it, 600851475143/2; is a darn big number. You might want to reconsider using it as a loop bound.

– user4581301
Nov 25 '18 at 21:42





g++ spits out warning: overflow in implicit constant conversion [-Woverflow] long int b = 600851475143/2; You should resolve this. Come to think of it, 600851475143/2; is a darn big number. You might want to reconsider using it as a loop bound.

– user4581301
Nov 25 '18 at 21:42













Regarding the prime computation, this is a brutally slow way to do this. Consider the number of times you are recomputing the i = 2 case.

– user4581301
Nov 25 '18 at 21:45





Regarding the prime computation, this is a brutally slow way to do this. Consider the number of times you are recomputing the i = 2 case.

– user4581301
Nov 25 '18 at 21:45













I didn't complete the previous thought. Use memoization to reduce the amount of redundant work you have to do. See if you can take advantage of a Prime Number Sieve.

– user4581301
Nov 25 '18 at 22:01





I didn't complete the previous thought. Use memoization to reduce the amount of redundant work you have to do. See if you can take advantage of a Prime Number Sieve.

– user4581301
Nov 25 '18 at 22:01












2 Answers
2






active

oldest

votes


















0














Add a cout statement inside the for loop in main. Your program is running, it's just taking a long time.






share|improve this answer































    0














    The code is fine. 600851475143/2 is just a large number, so you have to wait some minutes till the result will be printed.
    Further you're testing kind of twice if it a prime which makes the complexity unnecessarily much higher.
    Try this:



    long int b = 600851475143/2;
    long int k = b;
    for(long int i = 2; i < b ; i++)
    {
    if(b % i == 0)
    {
    k = i;
    break;
    }
    }
    cout << k << endl;





    share|improve this answer


























    • I think the problem is given for this. Maybe there is more optimal way to solve this problem ?

      – Mane Hambardzumyan
      Nov 25 '18 at 21:45











    • @ManeHambardzumyan Look into cryptography. Factoring huge numbers into primes is something they do every day and they have a lot of tricks to make it easier to compute.

      – user4581301
      Nov 25 '18 at 21:59













    Your Answer






    StackExchange.ifUsing("editor", function () {
    StackExchange.using("externalEditor", function () {
    StackExchange.using("snippets", function () {
    StackExchange.snippets.init();
    });
    });
    }, "code-snippets");

    StackExchange.ready(function() {
    var channelOptions = {
    tags: "".split(" "),
    id: "1"
    };
    initTagRenderer("".split(" "), "".split(" "), channelOptions);

    StackExchange.using("externalEditor", function() {
    // Have to fire editor after snippets, if snippets enabled
    if (StackExchange.settings.snippets.snippetsEnabled) {
    StackExchange.using("snippets", function() {
    createEditor();
    });
    }
    else {
    createEditor();
    }
    });

    function createEditor() {
    StackExchange.prepareEditor({
    heartbeatType: 'answer',
    autoActivateHeartbeat: false,
    convertImagesToLinks: true,
    noModals: true,
    showLowRepImageUploadWarning: true,
    reputationToPostImages: 10,
    bindNavPrevention: true,
    postfix: "",
    imageUploader: {
    brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
    contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
    allowUrls: true
    },
    onDemand: true,
    discardSelector: ".discard-answer"
    ,immediatelyShowMarkdownHelp:true
    });


    }
    });














    draft saved

    draft discarded


















    StackExchange.ready(
    function () {
    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53472211%2fconsole-application-is-not-running-and-shows-nothing%23new-answer', 'question_page');
    }
    );

    Post as a guest















    Required, but never shown

























    2 Answers
    2






    active

    oldest

    votes








    2 Answers
    2






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    0














    Add a cout statement inside the for loop in main. Your program is running, it's just taking a long time.






    share|improve this answer




























      0














      Add a cout statement inside the for loop in main. Your program is running, it's just taking a long time.






      share|improve this answer


























        0












        0








        0







        Add a cout statement inside the for loop in main. Your program is running, it's just taking a long time.






        share|improve this answer













        Add a cout statement inside the for loop in main. Your program is running, it's just taking a long time.







        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered Nov 25 '18 at 21:38









        SavithruSavithru

        602511




        602511

























            0














            The code is fine. 600851475143/2 is just a large number, so you have to wait some minutes till the result will be printed.
            Further you're testing kind of twice if it a prime which makes the complexity unnecessarily much higher.
            Try this:



            long int b = 600851475143/2;
            long int k = b;
            for(long int i = 2; i < b ; i++)
            {
            if(b % i == 0)
            {
            k = i;
            break;
            }
            }
            cout << k << endl;





            share|improve this answer


























            • I think the problem is given for this. Maybe there is more optimal way to solve this problem ?

              – Mane Hambardzumyan
              Nov 25 '18 at 21:45











            • @ManeHambardzumyan Look into cryptography. Factoring huge numbers into primes is something they do every day and they have a lot of tricks to make it easier to compute.

              – user4581301
              Nov 25 '18 at 21:59


















            0














            The code is fine. 600851475143/2 is just a large number, so you have to wait some minutes till the result will be printed.
            Further you're testing kind of twice if it a prime which makes the complexity unnecessarily much higher.
            Try this:



            long int b = 600851475143/2;
            long int k = b;
            for(long int i = 2; i < b ; i++)
            {
            if(b % i == 0)
            {
            k = i;
            break;
            }
            }
            cout << k << endl;





            share|improve this answer


























            • I think the problem is given for this. Maybe there is more optimal way to solve this problem ?

              – Mane Hambardzumyan
              Nov 25 '18 at 21:45











            • @ManeHambardzumyan Look into cryptography. Factoring huge numbers into primes is something they do every day and they have a lot of tricks to make it easier to compute.

              – user4581301
              Nov 25 '18 at 21:59
















            0












            0








            0







            The code is fine. 600851475143/2 is just a large number, so you have to wait some minutes till the result will be printed.
            Further you're testing kind of twice if it a prime which makes the complexity unnecessarily much higher.
            Try this:



            long int b = 600851475143/2;
            long int k = b;
            for(long int i = 2; i < b ; i++)
            {
            if(b % i == 0)
            {
            k = i;
            break;
            }
            }
            cout << k << endl;





            share|improve this answer















            The code is fine. 600851475143/2 is just a large number, so you have to wait some minutes till the result will be printed.
            Further you're testing kind of twice if it a prime which makes the complexity unnecessarily much higher.
            Try this:



            long int b = 600851475143/2;
            long int k = b;
            for(long int i = 2; i < b ; i++)
            {
            if(b % i == 0)
            {
            k = i;
            break;
            }
            }
            cout << k << endl;






            share|improve this answer














            share|improve this answer



            share|improve this answer








            edited Nov 25 '18 at 21:46

























            answered Nov 25 '18 at 21:41









            goarangoaran

            446




            446













            • I think the problem is given for this. Maybe there is more optimal way to solve this problem ?

              – Mane Hambardzumyan
              Nov 25 '18 at 21:45











            • @ManeHambardzumyan Look into cryptography. Factoring huge numbers into primes is something they do every day and they have a lot of tricks to make it easier to compute.

              – user4581301
              Nov 25 '18 at 21:59





















            • I think the problem is given for this. Maybe there is more optimal way to solve this problem ?

              – Mane Hambardzumyan
              Nov 25 '18 at 21:45











            • @ManeHambardzumyan Look into cryptography. Factoring huge numbers into primes is something they do every day and they have a lot of tricks to make it easier to compute.

              – user4581301
              Nov 25 '18 at 21:59



















            I think the problem is given for this. Maybe there is more optimal way to solve this problem ?

            – Mane Hambardzumyan
            Nov 25 '18 at 21:45





            I think the problem is given for this. Maybe there is more optimal way to solve this problem ?

            – Mane Hambardzumyan
            Nov 25 '18 at 21:45













            @ManeHambardzumyan Look into cryptography. Factoring huge numbers into primes is something they do every day and they have a lot of tricks to make it easier to compute.

            – user4581301
            Nov 25 '18 at 21:59







            @ManeHambardzumyan Look into cryptography. Factoring huge numbers into primes is something they do every day and they have a lot of tricks to make it easier to compute.

            – user4581301
            Nov 25 '18 at 21:59




















            draft saved

            draft discarded




















































            Thanks for contributing an answer to Stack Overflow!


            • Please be sure to answer the question. Provide details and share your research!

            But avoid



            • Asking for help, clarification, or responding to other answers.

            • Making statements based on opinion; back them up with references or personal experience.


            To learn more, see our tips on writing great answers.




            draft saved


            draft discarded














            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53472211%2fconsole-application-is-not-running-and-shows-nothing%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown





















































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown

































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown







            Popular posts from this blog

            Contact image not getting when fetch all contact list from iPhone by CNContact

            count number of partitions of a set with n elements into k subsets

            A CLEAN and SIMPLE way to add appendices to Table of Contents and bookmarks