Longest Substring without repeating Characters2015 year June 9

string " ABCABCBB "is" ABC ", which the length is 3. For "bbbbb" the longest substring are "B", with the length of 1.

Initial solution:

Idea: To find out all successive substrings, and then to determine whether each substring has duplicate elements

If the original string length is n, the number of all substrings is C (n,2) = n+n-1+...+1;

 Public classSolution { Public intlengthoflongestsubstring (String s) {intLength =s.length (); BooleanReflag =false; intMax = 0; List<String> lists =NewArraylist<string> ();  for(inti=0; i<length; i++) {             for(intj=i+1; j<length; J + +) {Lists.add (s.substring (i,j+1)); }        }                 for(String ssub:lists) {Reflag=false;  for(inti=0; I<ssub.length (); i++){                Charc =Ssub.charat (i); if(Ssub.indexof (c,i+1)!=-1) {Reflag=true;  Break; }            }                        if(!Reflag) {                intSublen =ssub.length (); if(Sublen >max) {Max=Sublen; }            }        }        returnMax; }    }

View Code

     Public Static voidMain (string[] args) {String s= "Abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz0123456789!\" #$%& "; BooleanReflag =false; intmax = 1; List<String> lists=NewArraylist<string>(); intLength =s.length ();  for(inti=0; i<length; i++) {             for(intj=i+1; j<length; J + +) {Lists.add (S.substring (i, J+1)); }        }         for(String subs:lists) {Reflag=false;  for(inti=0; I<subs.length (); i++){                Charc =Subs.charat (i); if(Subs.indexof (c, i+1)!=-1) {Reflag=true;  Break; }            }                        if(!Reflag) {                intSpace =subs.length (); if(Space >max) {Max=space;        }}} System.out.println (max);        System.out.println (Lists.size ());    System.out.println (Lists.tostring ()); }

This method does not pass the Leetcode test, but is logically correct, and for a particularly long string, a timeout error is indicated.

Improved method:

Edge find substring to determine if the substring repeats.

Longest Substring without repeating Characters2015 June 9