Determines whether a number contains two identical substrings and outputs

Function: Determine whether a number contains two identical substrings (at least the string length is greater than or equal to 2) and outputs (output only the same substring for the first time)

1  PackageRen.laughing.test.problem;2 3 ImportJava.util.Scanner;4 5 /**6 * Function: Determine if a number contains two identical substrings (at least the string length is greater than or equal to 2) and output (output only the same substring for the first time)7  * 8  * @authorLaughing_lz9 * @time July 4, 2016Ten  */ One  Public classChildstr { A     PrivateString str; -  -     /** the * Determine if the input string is legal -      */ -      Public voidinput () { -Scanner sc =NewScanner (system.in); +str =sc.nextline (); - sc.close (); +         if(Str.isempty ()) {//if the input is empty Astr =NULL; at             return; -         } -          for(inti = 0; I < str.length (); i++) { -             Charc =Str.charat (i); -             if(Str.isempty () | | | (c >= ' a ' && c <= ' z ') | | (c >= ' A ' && C <= ' Z ') | | (c >= ' 0 ' && C <= ' 9 '))) {//Restriction conditions -str =NULL; in                 return; -             } to         } +     } -  the     /** * * Search Algorithm $      */Panax Notoginseng      Public voidsearch () { -         if(str = =NULL) { theSystem.out.println ("Input string Error! "); +             return; A         } the         intj = 1;//The index is defined here out of two loops and can be implemented in a single loop with J always and I synchronized progression ★ +         intNumber = 0;//record the same substring length -         intindex = 0;//record string start position $          for(inti = 0; I < Str.length ()-1; i++) { $             CharNumi = Str.charat (i);//Current Position number -             if(i = = Str.length ()-2 | | j = =str.length ()) { -Number = 0;//return number to 0 thej = i + 1;//after a loop, move J back to the i+1 start point and traverse -             }Wuyi              for(; J < Str.length (); j + +) { the                 CharNUMJ =Str.charat (j); -                 if(Numi = =NUMJ) { Wunumber++; -                     if(J < Str.length ()-1) { Aboutj + +;//before judging the next number, J + + $                     } -                      Break; -}Else { -                     if(Number >= 2) { A                          Break; +}Else { theNumber = 0;//if only 1 digits are encountered, place number 0 when different numbers are encountered -                     } $                 } the             } the             if(Number >= 2 && str.charat (i + 1)! = Str.charat (j)) {//when the same number is greater than 2, a different number is encountered immediately exiting the loop, printing the substring theindex = i + 1; the                  Break; -             } in         } the         if(Number >= 2) { theSystem.out.println ("exists, string is:" + str.substring (Index-Number , index)); About         } the     } the  the      Public Static voidMain (String arg[]) { +CHILDSTR cs =Newchildstr (); - cs.input (); the Cs.search ();Bayi     } the}

Determines whether a number contains two identical substrings and outputs