蓝桥杯练习题 字符串变换

 1 import java.util.Scanner;
 2 
 3 
 4 public class Main {
 5     
 6     public static void main(String[] args) {
 7         // TODO Auto-generated method stub
 8         Scanner input = new Scanner(System.in);
 9         int n=input.nextInt();
10         String s =input.next();
11         char[] a=s.toCharArray();
12         switch (n) {
13             case 1:
14                 s=s.toUpperCase();
15                 System.out.println(s);
16                 break;
17             case 2:
18                 s=s.toLowerCase();
19                 System.out.println(s);
20                 break;
21             case 3:
22                 for(int i=0;i<s.length()/2;i++)
23                 {
24                     int j=s.length()-i-1;
25                     char c=a[i];
26                     a[i]=a[j];
27                     a[j]=c;
28                     j--;
29                 }
30                 s=String.valueOf(a);
31                 System.out.println(s);
32                 break;
33             case 4:
34                 for(int i=0;i<s.length();i++)
35                 {
36                     char c= s.charAt(i);
37                     if(Character.isUpperCase(c))
38                     {
39                         a[i]=Character.toLowerCase(c);
40                     }
41                     else
42                         a[i]=Character.toUpperCase(c);
43                 }
44                 s=String.valueOf(a);
45                 System.out.println(s);
46                 break;
47             case 5:
48                 s=s.toLowerCase();
49                 a=s.toCharArray();
50                 int count=0;
51                 
52                 System.out.print(a[0]);
53                 for(int i=1;i<s.length();i++)
54                 {
55                     
56                     while(a[i]-a[i-1]==1)
57                     {
58                         count++;
59                         i++;
60                         if(i>=s.length())
61                             break;
62                     }
63                     if(count>1)
64                     {
65                         System.out.print("-"+a[--i]);
66                     }
67                     else
68                     {
69                         if(count>0)
70                             i--;
71                         System.out.print(a[i]);
72                     }
73                     count=0;
74                 }
75                 break;
76             default:
77                 break;
78         }
79         
80         
81     }
82 
83 
84     
85 }