Java implementation-Three swords per day offre (2-4)

2. Implement a single case mode

1 /**2 * Face question 2: Implementing a singleton pattern3  * 4  * @authorQiuyong a hungry man type5  */6  Public classSingleton01 {7     PrivateSingleton01 () {8     }9 Ten     Private StaticSingleton01 instance =NewSingleton01 (); One  A      Public StaticSingleton01 getinstance () { -         returninstance; -      the     } - } -  - /** + * Face question 2: lazy type -  * @authorQiuyong +  */ A  Public classSINGLETON02 { at      -      Public StaticSINGLETON02 instance; -      -      Public synchronized StaticSingleton02 getinstance () { -         if(NULL==instance) { -Instance=NewSingleton02 (); in         }         -         returninstance; to     } +  - } the  * /** $ * Face question 2: using internal classesPanax Notoginseng  * @authorQiuyong -  */ the  Public classSingleton03 { +      A      Public StaticSingleton03 getinstance () { the         returninnerclass.instatnce; +     } -      $     Private Static classinnerclass{ $          Public StaticSingleton03 instatnce=NewSingleton03 (); -     } -}

3, two-dimensional array lookup

　　Title Description: A two-dimensional array with each row incrementing from left to right and each column incrementing from top to bottom. Enter a two-dimensional array and an integer to determine if the array contains integers.

 Public classTest { Public Static BooleanFindint[] Arry,intnum) {        intColumn=arry[0].length-1; intRow=0;  while(row<arry.length&&column>=0){            if(num==Arry[row][column]) {                return true; }            if(arry[row][column]>num) {Column--; }Else{row++; }                    }        return false; }         Public Static voidMain (string[] args) {int[] arry=New int[3] [3];  for(inti=0;i<arry.length;i++){             for(intj=0;j<arry[0].length;j++) {Arry[i][j]= (i+1) * (j+1); }} System.out.println ("See if there is element 9:" +find (arry,9)); System.out.println ("See if there is element 9:" +find (arry,0)); }}

4. Replace Space

　　Title Description: Implement a function that replaces each space in the string with "%20".

1  Public classReplaceblank {2      Public Static voidMain (string[] args) {3String str= "I am happy";4Str=Replaceblank (str);5 System.out.println (str);6     }7     8     9      Public Staticstring Replaceblank (String str) {Ten         if(NULL==str) { One             return NULL; A         } -StringBuffer sb=NewStringBuffer (); -          for(intI=0;i<str.length (); i++){ the             if(Str.charat (i) = = "){ -Sb.append ("%20"); -}Else{ - Sb.append (Str.charat (i)); +             } -         } +         returnsb.tostring (); A     } at  -}

Java implementation-Three swords per day offre (2-4)