Programmer horse - the same maximum take two strings substring

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1  / * 
2      Find the longest string of the same two strings
 . 3  * / 
. 4  
. 5  class the Compare {
 . 6       // Find the longest After the same string by subscript 
. 7      public String lastCompare (STR String, String str2) throws {a NullPointerException
 . 8          return Compare (ifAndToString (STR, str2), "Last" );
 . 9      }
 10      // Find the subscript front longest substring same 
. 11      public String firstCompare (STR String, String str2) throws a NullPointerException {
 12 is          return Compare (ifAndToString (STR, str2), "First" );
 13 is      }
14      // string length of the teaching is processed to identify all of the same string two strings 
15      Private String ifAndToString (STR String, String str2) throws a NullPointerException {
 16          String Str3 = null ;
 . 17          String = LONGCHAR " " ;
 18          // If the incoming data is illegal 
19          IF (str == null && str2 == null && str ==" "&& str2 ==" " )
 20              the throw  new new NullPointerException (" Sorry illegal data into "! ) ;
 21              // length of the string at a position below the operation easy exchange 
22 is          IF (str.length () < str2.length()){
23 is              String TEMP = STR;
 24              STR = str2;
 25              str2 = TEMP;
 26 is          }
 27          IF (! Str.indexOf (str2) = -1 ) {
 28              return str2;
 29          } the else {
 30              // short cycle of characters indexOf operation 
31 is              for ( int I = 0; I <str2.length (); I ++ ) {
 32                  for ( int J = str2.length () -. 1; J> I; J, ) {
 33 is                      IF (str.indexOf (Str3 str2.substring = (I, J))! = -1 ) {
34                          // the same string into a string separated by commas, the array directly I thought, but not define the length 
35                          LONGCHAR + = "," + Str3;
 36                      }
 37 [                  }
 38 is              }
 39          }
 40          return LONGCHAR;
 41 is      }
 42 is      // removed longest string 
43 is      Private String Compare (LONGCHAR String, String Order) {
 44 is          IF ( "" .equals (LONGCHAR))
 45              return LONGCHAR;
 46 is          String [] = ARR LONGCHAR. Split ( "," );
 47          int index = 0;
48         //判断取靠前字串还是靠后的
49         if("first".equals(order)){
50             for(int i = 1; i<arr.length; i++){
51                 if(arr[index].length() < arr[i].length())
52                     index = i;
53             }
54         }else{
55             for(int i = arr.length - 1; i>0; i--){
56                 if(arr[index].length() < arr[i].length())
57                     index = i;
58             }
59         }
60         return arr[index];
61     }
62 }
63 
64 class XiangTongZiChuan{
65     public static void main(String[] args){
66         String str = "sdfasfdshelloewfwfeeeee";
67         String str2 = "ssfdfhelloe";
68         try{
69             Compare cm = new Compare();
70             System.out.println(cm.lastCompare(str,str2));
71         }catch(NullPointerException e){
72             e.printStackTrace();
73         }
74     }
75 }

 

Essay experience: 1 if there is a direct throw an exception return to the special circumstances of the election may determine such special circumstances do not write else optimized code in the method.

　　　　　2. In the above I judge the value of the array maximum length of time is to create a variable of type String constantly receiving new values ​​so that if the heap memory has also been created behind the String object I changed to record with a variable int under this standard, although it will continue to change the value of int variables but it does not create a lot of objects

Reproduced in: https: //www.cnblogs.com/wan-to-fly/archive/2013/01/30/2883366.html