转载 若干面试题目

1、字符串 “ A@B@C@D ”，以 @ 字符拆分 返回数组

1. String[] strs =  "A@B@C@D" .split( "@" );  

String[] strs = "A@B@C@D".split("@");

2 、字符串 String s= ” SDsBEaA ” , 要求最后生成 s= ” AaBDESs ”

1. import  java.util.*;  
2. public   class  Test{  
3.     public   static   void  main(String[] args) {  
4.         //System.out.println(countBits(-1));   
5.         System.out.println(sortString("SDsBEaA" ));  
6.     }  
7. //排序方法    public static String sortString(String str){   
8.         Character[] characters=new  Character[str.length()];  
9.         char [] strchars=str.toCharArray();  
10.         int  count= 0 ;  
11.         for ( char  c:strchars){  
12.             characters[count++]=c;  
13.         }  
14. //采用匿名类的方式重写比较方法类   
15.   
16.         Arrays.sort(characters,new  Comparator<Character>(){  
17.             public   int  compare(Character c1,Character c2){  
18.                 if (c1.equals(c2)) return   0 ;  
19.                 if (Character.toLowerCase(c1)==Character.toLowerCase(c2)){  
20.                     return  c1-c2;  
21.                 }else {  
22.                     return  Character.toLowerCase(c1)-Character.toLowerCase(c2);  
23.                 }  
24.             }  
25.             public   boolean  equals(Object o){  
26.                 return   true ;  
27.             }  
28.         });  
29.         count=0 ;  
30.         for (Character c: characters){  
31.             strchars[count++]=c;  
32.         }  
33.         return   new  String(strchars);  
34.   
35.     }  
36. }  

import java.util.*; public class Test{ public static void main(String[] args) { //System.out.println(countBits(-1)); System.out.println(sortString("SDsBEaA")); } //排序方法 public static String sortString(String str){ Character[] characters=new Character[str.length()]; char[] strchars=str.toCharArray(); int count=0; for(char c:strchars){ characters[count++]=c; } //采用匿名类的方式重写比较方法类 Arrays.sort(characters,new Comparator<Character>(){ public int compare(Character c1,Character c2){ if(c1.equals(c2))return 0; if(Character.toLowerCase(c1)==Character.toLowerCase(c2)){ return c1-c2; }else{ return Character.toLowerCase(c1)-Character.toLowerCase(c2); } } public boolean equals(Object o){ return true; } }); count=0; for(Character c: characters){ strchars[count++]=c; } return new String(strchars); } }

 

3、用HTML做出如下效果：

 

 

view plain copy to clipboard print ?

1. < table   width = "30%"   border = "0"   bgcolor = "#000000" >     
2.             < tr >     
3.                 < td   colspan = "4"   bgcolor = "#FFFFFF" > 1 </ td >     
4.             </ tr >     
5.             < tr >     
6.                 < td   rowspan = "4"   bgcolor = "#FFFFFF" > 2 </ td >     
7.                 < td   colspan = "3"   bgcolor = "#FFFFFF" > 3 </ td >     
8.             </ tr >     
9.             < tr >     
10.                 < td   rowspan = "3"   bgcolor = "#FFFFFF" > 4 </ td >     
11.                 < td   colspan = "2"   bgcolor = "#FFFFFF" > 5 </ td >     
12.             </ tr >     
13.             < tr >     
14.                 < td   rowspan = "2"   bgcolor = "#FFFFFF" > 6 </ td >     
15.                 < td   bgcolor = "#FFFFFF" > 7 </ td >     
16.             </ tr >     
17.             < tr >     
18.                 < td   bgcolor = "#FFFFFF" > 8 </ td >     
19.             </ tr >     
20.         </ table >   

<table width="30%" border="0" bgcolor="#000000"> <tr> <td colspan="4" bgcolor="#FFFFFF">1</td> </tr> <tr> <td rowspan="4" bgcolor="#FFFFFF">2</td> <td colspan="3" bgcolor="#FFFFFF">3</td> </tr> <tr> <td rowspan="3" bgcolor="#FFFFFF">4</td> <td colspan="2" bgcolor="#FFFFFF">5</td> </tr> <tr> <td rowspan="2" bgcolor="#FFFFFF">6</td> <td bgcolor="#FFFFFF">7</td> </tr> <tr> <td bgcolor="#FFFFFF">8</td> </tr> </table>

4、给你一个字符串，包含了空格等标点符号，要你计算出出现次数最多的字母和该字母出现的次数。

 

1. public   static   void  main(String[] args) {         
2.        Map<String,Long> charTimesMap = new  HashMap<String,Long>();     
3.             
4.        String str = "hello wolrd wlllkcdfdfdfdfdfdfdfdsfhksadfl,,,,,,,,,,,,,,,,,,,,,s?sdfls  fjs" ;    
5.        str = str.replaceAll("[^a-zA-Z]" ,  "" );  
6.        //以字符为key，以出现次数为value存入Map中   
7.        for  ( char  each : str.toCharArray()) {     
8.               
9.                String charStr = String.valueOf(each);     
10.                if  (charTimesMap.containsKey(charStr)) {     
11.                    Long num = charTimesMap.get(charStr).longValue() + 1 ;     
12.                    charTimesMap.put(charStr, num);     
13.                } else  {     
14.                    charTimesMap.put(charStr, 1L);     
15.                }     
16.        }     
17.             
18.        String maxAppearChar = null ;     
19.        Long maxAppearTimes = 0L;     
20.        //遍历map，entrySet()方法取得map集合   
21.        for  (Map.Entry<String, Long> charAppear : charTimesMap.entrySet()) {     
22.            if  (charAppear.getValue() > maxAppearTimes) {     
23.                maxAppearChar = charAppear.getKey();     
24.                maxAppearTimes = charAppear.getValue();     
25.            }     
26.        }     
27.        System.out.println("出现最多的字母：" +maxAppearChar);     
28.        System.out.println("出现次数:" +maxAppearTimes);     
29.    }