Repeatedly keep removing 2 smallest elements and add its sum back to the list, till it reduces to a single number? Need optimization for million+Given a list of numbers and a number k, return whether any two numbers from the list add up to k

If Manufacturer spice model and Datasheet give different values which should I use?

Motorized valve interfering with button?

Why can't I see bouncing of a switch on an oscilloscope?

Mathematical cryptic clues

How old can references or sources in a thesis be?

Is it possible to make sharp wind that can cut stuff from afar?

Today is the Center

Shell script not opening as desktop application

A newer friend of my brother's gave him a load of baseball cards that are supposedly extremely valuable. Is this a scam?

declaring a variable twice in IIFE

Is there any sparring that doesn't involve punches to the head?

The use of multiple foreign keys on same column in SQL Server

I’m planning on buying a laser printer but concerned about the life cycle of toner in the machine

What is the offset in a seaplane's hull?

What do you call a Matrix-like slowdown and camera movement effect?

How did the USSR manage to innovate in an environment characterized by government censorship and high bureaucracy?

How to make payment on the internet without leaving a money trail?

What are these boxed doors outside store fronts in New York?

Infinite past with a beginning?

Awk syntax, strange variable?

Do Phineas and Ferb ever actually get busted in real time?

Can I interfere when another PC is about to be attacked?

XeLaTeX and pdfLaTeX ignore hyphenation

I probably found a bug with the sudo apt install function



Repeatedly keep removing 2 smallest elements and add its sum back to the list, till it reduces to a single number? Need optimization for million+


Given a list of numbers and a number k, return whether any two numbers from the list add up to k






.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty margin-bottom:0;








0












$begingroup$


I have a list of unsorted numbers. Each time, i need to remove 2 smallest numbers and insert back its sum into the list. Repeatedly do this till the 1 final element is remaining in the list.



My logic was to use heap sort, remove 2 elems, insert elems sum back - repeat



This program of input of 10 elements has called heapify function 310 times.!!



Link: http://cpp.sh/8vkjd



How do i optimize this scenario?
- Use Binary Search Tree?
- Use Heap Sort with LinkedList?
- Is this possible with graphs?
- Since there are several insertions, I'm trying to only restrict to O(N) or O(log N) or O(n log N) insertion.
- can this be done with 2 lists?
- since the elements will be sorted after the 1st iteration, is there a good insertion algorithm that does faster insertion



#include <iostream>
#include <sstream>
#include <vector>
int count = 0; // A global variable to keep track of number of time heapify function is called
void heapify(std::vector<int> &arr, int n, int i)

count++;
int largest = i;
int l = 2*i + 1;
int r = 2*i + 2;

if(l<n && arr[l] >arr[largest])
largest = l;

if(r<n && arr[r] > arr[largest])
largest = r;

if(largest != i)

std::swap(arr[i], arr[largest]);
heapify(arr, n, largest);



void heapSort(std::vector<int> &arr, int n)

for(int i=n/2 -1 ; i>=0 ; i--)

heapify(arr,n,i);



for(int i=n-1 ; i>=0 ; i--)

std::swap(arr[0],arr[i]);
heapify(arr,i,0);




void printArray(std::vector<int> &arr, int n)

for(int i=0 ; i<n ; i++)

std::cout << arr[i] << " ";

std::cout << std::endl;


int main()

std::vector<int> arr1,2,3,4,5,6,7,8,9,10;
int n = arr.size();
printArray(arr,n);
heapSort(arr,n);

int ans=0;
int tempEle=0;
while(arr.size()>1)

heapSort(arr,n);
tempEle = arr[0]+arr[1];
arr.erase(arr.begin(),arr.begin()+2);
ans+=tempEle;
arr.push_back(tempEle);
printArray(arr,arr.size());

ans+=arr[0];

std::cout << "Repeatedly adding all elements, 2 small elements at a time and reducing it to a single number : " << ans << std::endl;

std::cout << "Heapify was called " << count << " times" << std::endl;
return 0;









share







New contributor




Manjunath is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$


















    0












    $begingroup$


    I have a list of unsorted numbers. Each time, i need to remove 2 smallest numbers and insert back its sum into the list. Repeatedly do this till the 1 final element is remaining in the list.



    My logic was to use heap sort, remove 2 elems, insert elems sum back - repeat



    This program of input of 10 elements has called heapify function 310 times.!!



    Link: http://cpp.sh/8vkjd



    How do i optimize this scenario?
    - Use Binary Search Tree?
    - Use Heap Sort with LinkedList?
    - Is this possible with graphs?
    - Since there are several insertions, I'm trying to only restrict to O(N) or O(log N) or O(n log N) insertion.
    - can this be done with 2 lists?
    - since the elements will be sorted after the 1st iteration, is there a good insertion algorithm that does faster insertion



    #include <iostream>
    #include <sstream>
    #include <vector>
    int count = 0; // A global variable to keep track of number of time heapify function is called
    void heapify(std::vector<int> &arr, int n, int i)

    count++;
    int largest = i;
    int l = 2*i + 1;
    int r = 2*i + 2;

    if(l<n && arr[l] >arr[largest])
    largest = l;

    if(r<n && arr[r] > arr[largest])
    largest = r;

    if(largest != i)

    std::swap(arr[i], arr[largest]);
    heapify(arr, n, largest);



    void heapSort(std::vector<int> &arr, int n)

    for(int i=n/2 -1 ; i>=0 ; i--)

    heapify(arr,n,i);



    for(int i=n-1 ; i>=0 ; i--)

    std::swap(arr[0],arr[i]);
    heapify(arr,i,0);




    void printArray(std::vector<int> &arr, int n)

    for(int i=0 ; i<n ; i++)

    std::cout << arr[i] << " ";

    std::cout << std::endl;


    int main()

    std::vector<int> arr1,2,3,4,5,6,7,8,9,10;
    int n = arr.size();
    printArray(arr,n);
    heapSort(arr,n);

    int ans=0;
    int tempEle=0;
    while(arr.size()>1)

    heapSort(arr,n);
    tempEle = arr[0]+arr[1];
    arr.erase(arr.begin(),arr.begin()+2);
    ans+=tempEle;
    arr.push_back(tempEle);
    printArray(arr,arr.size());

    ans+=arr[0];

    std::cout << "Repeatedly adding all elements, 2 small elements at a time and reducing it to a single number : " << ans << std::endl;

    std::cout << "Heapify was called " << count << " times" << std::endl;
    return 0;









    share







    New contributor




    Manjunath is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
    Check out our Code of Conduct.







    $endgroup$














      0












      0








      0





      $begingroup$


      I have a list of unsorted numbers. Each time, i need to remove 2 smallest numbers and insert back its sum into the list. Repeatedly do this till the 1 final element is remaining in the list.



      My logic was to use heap sort, remove 2 elems, insert elems sum back - repeat



      This program of input of 10 elements has called heapify function 310 times.!!



      Link: http://cpp.sh/8vkjd



      How do i optimize this scenario?
      - Use Binary Search Tree?
      - Use Heap Sort with LinkedList?
      - Is this possible with graphs?
      - Since there are several insertions, I'm trying to only restrict to O(N) or O(log N) or O(n log N) insertion.
      - can this be done with 2 lists?
      - since the elements will be sorted after the 1st iteration, is there a good insertion algorithm that does faster insertion



      #include <iostream>
      #include <sstream>
      #include <vector>
      int count = 0; // A global variable to keep track of number of time heapify function is called
      void heapify(std::vector<int> &arr, int n, int i)

      count++;
      int largest = i;
      int l = 2*i + 1;
      int r = 2*i + 2;

      if(l<n && arr[l] >arr[largest])
      largest = l;

      if(r<n && arr[r] > arr[largest])
      largest = r;

      if(largest != i)

      std::swap(arr[i], arr[largest]);
      heapify(arr, n, largest);



      void heapSort(std::vector<int> &arr, int n)

      for(int i=n/2 -1 ; i>=0 ; i--)

      heapify(arr,n,i);



      for(int i=n-1 ; i>=0 ; i--)

      std::swap(arr[0],arr[i]);
      heapify(arr,i,0);




      void printArray(std::vector<int> &arr, int n)

      for(int i=0 ; i<n ; i++)

      std::cout << arr[i] << " ";

      std::cout << std::endl;


      int main()

      std::vector<int> arr1,2,3,4,5,6,7,8,9,10;
      int n = arr.size();
      printArray(arr,n);
      heapSort(arr,n);

      int ans=0;
      int tempEle=0;
      while(arr.size()>1)

      heapSort(arr,n);
      tempEle = arr[0]+arr[1];
      arr.erase(arr.begin(),arr.begin()+2);
      ans+=tempEle;
      arr.push_back(tempEle);
      printArray(arr,arr.size());

      ans+=arr[0];

      std::cout << "Repeatedly adding all elements, 2 small elements at a time and reducing it to a single number : " << ans << std::endl;

      std::cout << "Heapify was called " << count << " times" << std::endl;
      return 0;









      share







      New contributor




      Manjunath is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.







      $endgroup$




      I have a list of unsorted numbers. Each time, i need to remove 2 smallest numbers and insert back its sum into the list. Repeatedly do this till the 1 final element is remaining in the list.



      My logic was to use heap sort, remove 2 elems, insert elems sum back - repeat



      This program of input of 10 elements has called heapify function 310 times.!!



      Link: http://cpp.sh/8vkjd



      How do i optimize this scenario?
      - Use Binary Search Tree?
      - Use Heap Sort with LinkedList?
      - Is this possible with graphs?
      - Since there are several insertions, I'm trying to only restrict to O(N) or O(log N) or O(n log N) insertion.
      - can this be done with 2 lists?
      - since the elements will be sorted after the 1st iteration, is there a good insertion algorithm that does faster insertion



      #include <iostream>
      #include <sstream>
      #include <vector>
      int count = 0; // A global variable to keep track of number of time heapify function is called
      void heapify(std::vector<int> &arr, int n, int i)

      count++;
      int largest = i;
      int l = 2*i + 1;
      int r = 2*i + 2;

      if(l<n && arr[l] >arr[largest])
      largest = l;

      if(r<n && arr[r] > arr[largest])
      largest = r;

      if(largest != i)

      std::swap(arr[i], arr[largest]);
      heapify(arr, n, largest);



      void heapSort(std::vector<int> &arr, int n)

      for(int i=n/2 -1 ; i>=0 ; i--)

      heapify(arr,n,i);



      for(int i=n-1 ; i>=0 ; i--)

      std::swap(arr[0],arr[i]);
      heapify(arr,i,0);




      void printArray(std::vector<int> &arr, int n)

      for(int i=0 ; i<n ; i++)

      std::cout << arr[i] << " ";

      std::cout << std::endl;


      int main()

      std::vector<int> arr1,2,3,4,5,6,7,8,9,10;
      int n = arr.size();
      printArray(arr,n);
      heapSort(arr,n);

      int ans=0;
      int tempEle=0;
      while(arr.size()>1)

      heapSort(arr,n);
      tempEle = arr[0]+arr[1];
      arr.erase(arr.begin(),arr.begin()+2);
      ans+=tempEle;
      arr.push_back(tempEle);
      printArray(arr,arr.size());

      ans+=arr[0];

      std::cout << "Repeatedly adding all elements, 2 small elements at a time and reducing it to a single number : " << ans << std::endl;

      std::cout << "Heapify was called " << count << " times" << std::endl;
      return 0;







      c++ algorithm sorting tree heap





      share







      New contributor




      Manjunath is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.










      share







      New contributor




      Manjunath is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.








      share



      share






      New contributor




      Manjunath is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.









      asked 4 mins ago









      ManjunathManjunath

      12




      12




      New contributor




      Manjunath is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.





      New contributor





      Manjunath is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.






      Manjunath is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.




















          0






          active

          oldest

          votes












          Your Answer





          StackExchange.ifUsing("editor", function ()
          return StackExchange.using("mathjaxEditing", function ()
          StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix)
          StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["\$", "\$"]]);
          );
          );
          , "mathjax-editing");

          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: "196"
          ;
          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: false,
          noModals: true,
          showLowRepImageUploadWarning: true,
          reputationToPostImages: null,
          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
          );



          );






          Manjunath is a new contributor. Be nice, and check out our Code of Conduct.









          draft saved

          draft discarded


















          StackExchange.ready(
          function ()
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fcodereview.stackexchange.com%2fquestions%2f217034%2frepeatedly-keep-removing-2-smallest-elements-and-add-its-sum-back-to-the-list-t%23new-answer', 'question_page');

          );

          Post as a guest















          Required, but never shown

























          0






          active

          oldest

          votes








          0






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes








          Manjunath is a new contributor. Be nice, and check out our Code of Conduct.









          draft saved

          draft discarded


















          Manjunath is a new contributor. Be nice, and check out our Code of Conduct.












          Manjunath is a new contributor. Be nice, and check out our Code of Conduct.











          Manjunath is a new contributor. Be nice, and check out our Code of Conduct.














          Thanks for contributing an answer to Code Review Stack Exchange!


          • 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.

          Use MathJax to format equations. MathJax reference.


          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%2fcodereview.stackexchange.com%2fquestions%2f217034%2frepeatedly-keep-removing-2-smallest-elements-and-add-its-sum-back-to-the-list-t%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

          बाताम इन्हें भी देखें सन्दर्भ दिक्चालन सूची1°05′00″N 104°02′0″E / 1.08333°N 104.03333°E / 1.08333; 104.033331°05′00″N 104°02′0″E / 1.08333°N 104.03333°E / 1.08333; 104.03333

          Why is the 'in' operator throwing an error with a string literal instead of logging false?Why can't I use switch statement on a String?Python join: why is it string.join(list) instead of list.join(string)?Multiline String Literal in C#Why does comparing strings using either '==' or 'is' sometimes produce a different result?How to initialize an array's length in javascript?How can I print literal curly-brace characters in python string and also use .format on it?Why does ++[[]][+[]]+[+[]] return the string “10”?Why is char[] preferred over String for passwords?Why does this code using random strings print “hello world”?jQuery.inArray(), how to use it right?

          How can we generalize the fact of finite dimensional vector space to an infinte dimensional case?$k[x]$-module and cyclic module over a finite dimensional vector spaceSubspace of a finite dimensional space is finite dimensionalIf V is an infinite-dimensional vector space, and S is an infinite-dimensional subspace of V, must the dimension of V/S be finite? ExplainWhy is an infinite dimensional space so different than a finite dimensional one?base for finite dimensional vector space is not infinite dimensional vector space?Any finite-dimensional vector space is the dual space of anotherHaving Trouble Understanding Meaning Of A Finite-Dimensional Vector SpaceProve that “Every subspaces of a finite-dimensional vector space is finite-dimensional”Ring as a finite dimensional Vector space over a field KQuestion regarding basis and dimension