The smallest-sum game












2












$begingroup$


The game is a function of an integer $ngeq 1$ and a number $tin(0,n)$.



An adversary picks $n$ numbers in $[0,1]$ whose total sum is $t$. You divide the numbers into two subsets and the adversary picks one of them. Your score is the sum of numbers in the remaining subset.



What is the largest sum $s(n,t)$ that you can guarantee?





  • $s(1,t) = 0$ - one subset will always be empty.


  • $s(2,t) = max(0, t-1)$ - each subset will contain one number. The adversary will try to make them as unbalanced as possible, and the worst he can do is make the larger number equal 1 so you get the smaller one which is $t-1$.


  • $s(3,t) = min(t/3, max(t-1,0))$ - the optimal division for you is apparently to put the two smallest numbers in one subset and the largest number in the other subset, so the adversary will try to make these subsets as unbalanced as possible. One way to do it is to make all numbers equal, in which case your score is $t/3$; another way is to make the largest number 1, in which case your score is $t-1$. The adversary will pick the worst of these two options.


For $ngeq 4$, the game becomes much more complex to analyze, since there are many different possible partitions. Do you see any pattern? Any way to make it simpler?










share|cite|improve this question









$endgroup$

















    2












    $begingroup$


    The game is a function of an integer $ngeq 1$ and a number $tin(0,n)$.



    An adversary picks $n$ numbers in $[0,1]$ whose total sum is $t$. You divide the numbers into two subsets and the adversary picks one of them. Your score is the sum of numbers in the remaining subset.



    What is the largest sum $s(n,t)$ that you can guarantee?





    • $s(1,t) = 0$ - one subset will always be empty.


    • $s(2,t) = max(0, t-1)$ - each subset will contain one number. The adversary will try to make them as unbalanced as possible, and the worst he can do is make the larger number equal 1 so you get the smaller one which is $t-1$.


    • $s(3,t) = min(t/3, max(t-1,0))$ - the optimal division for you is apparently to put the two smallest numbers in one subset and the largest number in the other subset, so the adversary will try to make these subsets as unbalanced as possible. One way to do it is to make all numbers equal, in which case your score is $t/3$; another way is to make the largest number 1, in which case your score is $t-1$. The adversary will pick the worst of these two options.


    For $ngeq 4$, the game becomes much more complex to analyze, since there are many different possible partitions. Do you see any pattern? Any way to make it simpler?










    share|cite|improve this question









    $endgroup$















      2












      2








      2





      $begingroup$


      The game is a function of an integer $ngeq 1$ and a number $tin(0,n)$.



      An adversary picks $n$ numbers in $[0,1]$ whose total sum is $t$. You divide the numbers into two subsets and the adversary picks one of them. Your score is the sum of numbers in the remaining subset.



      What is the largest sum $s(n,t)$ that you can guarantee?





      • $s(1,t) = 0$ - one subset will always be empty.


      • $s(2,t) = max(0, t-1)$ - each subset will contain one number. The adversary will try to make them as unbalanced as possible, and the worst he can do is make the larger number equal 1 so you get the smaller one which is $t-1$.


      • $s(3,t) = min(t/3, max(t-1,0))$ - the optimal division for you is apparently to put the two smallest numbers in one subset and the largest number in the other subset, so the adversary will try to make these subsets as unbalanced as possible. One way to do it is to make all numbers equal, in which case your score is $t/3$; another way is to make the largest number 1, in which case your score is $t-1$. The adversary will pick the worst of these two options.


      For $ngeq 4$, the game becomes much more complex to analyze, since there are many different possible partitions. Do you see any pattern? Any way to make it simpler?










      share|cite|improve this question









      $endgroup$




      The game is a function of an integer $ngeq 1$ and a number $tin(0,n)$.



      An adversary picks $n$ numbers in $[0,1]$ whose total sum is $t$. You divide the numbers into two subsets and the adversary picks one of them. Your score is the sum of numbers in the remaining subset.



      What is the largest sum $s(n,t)$ that you can guarantee?





      • $s(1,t) = 0$ - one subset will always be empty.


      • $s(2,t) = max(0, t-1)$ - each subset will contain one number. The adversary will try to make them as unbalanced as possible, and the worst he can do is make the larger number equal 1 so you get the smaller one which is $t-1$.


      • $s(3,t) = min(t/3, max(t-1,0))$ - the optimal division for you is apparently to put the two smallest numbers in one subset and the largest number in the other subset, so the adversary will try to make these subsets as unbalanced as possible. One way to do it is to make all numbers equal, in which case your score is $t/3$; another way is to make the largest number 1, in which case your score is $t-1$. The adversary will pick the worst of these two options.


      For $ngeq 4$, the game becomes much more complex to analyze, since there are many different possible partitions. Do you see any pattern? Any way to make it simpler?







      combinatorial-game-theory






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Jan 19 at 19:39









      Erel Segal-HaleviErel Segal-Halevi

      4,33011861




      4,33011861






















          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.ready(function() {
          var channelOptions = {
          tags: "".split(" "),
          id: "69"
          };
          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
          },
          noCode: true, onDemand: true,
          discardSelector: ".discard-answer"
          ,immediatelyShowMarkdownHelp:true
          });


          }
          });














          draft saved

          draft discarded


















          StackExchange.ready(
          function () {
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3079724%2fthe-smallest-sum-game%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
















          draft saved

          draft discarded




















































          Thanks for contributing an answer to Mathematics 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%2fmath.stackexchange.com%2fquestions%2f3079724%2fthe-smallest-sum-game%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

          android studio warns about leanback feature tag usage required on manifest while using Unity exported app?

          SQL update select statement

          'app-layout' is not a known element: how to share Component with different Modules