【java】文件操作小測——統計英文文本出現頻率最高的字母

一、題目描述

 二、基本思路

通過FileReader讀取到文件，通過readLine讀取字符串，拆成字符進行判斷，這裏使用最笨的方法用大小為52的數組存儲各個字母出現的頻次，通過ascii碼聯係數字與字母，排序後輸出即可。

三、源碼及結果

 1 import java.io.BufferedReader;
 2 import java.io.File;
 3 import java.io.FileReader;
 4 import java.text.DecimalFormat;
 5
 6 public class sumNovel {
 7
 8     public static void main(String[] args) {
 9         // TODO Auto-generated method stub
10         File f = new File("Harry Potter and the Sorcerer's Stone.txt");
11         FileReader fr = null;
12         BufferedReader br = null;
13         try {
14             DecimalFormat df = new DecimalFormat("0.00");
15             fr = new FileReader(f);
16             br = new BufferedReader(fr);
17             String str = null;
18             double[] sum = new double[52];
19             double[] result = new double[52];
20             int[] order = new int[52];
21             for(int i=0;i<52;i++)
22             {
23                 sum[i] = 0;
24                 order[i] = i;
25             }
26             double all = 0;
27             while((str = br.readLine())!=null)
28             {
29                 char[] array = str.toCharArray();
30                 for(int i=0;i<array.length;i++)
31                 {
32                     int x = Integer.valueOf(array[i]);
33                     if(x>=65&&x<=90)
34                     {
35                         int j=x-65;
36                         sum[j]++;
37                         all++;
38                     }else if(x>=97&&x<=122)
39                     {
40                         int j=x-97+26;
41                         sum[j]++;
42                         all++;
43                     }
44                 }
45             }
46             for(int i=0;i<52;i++)
47             {
48                 result[i] = sum[i]/all;
49             }
50
51             for (int i = 0; i < 52; i++) {
52                 int maxIndex = i;
53                 for (int j = i; j < 52; j++) {
54                     if (result[order[j]] > result[order[maxIndex]])
55                         maxIndex = j;
56                 }
57                 int temp = order[maxIndex];
58                 order[maxIndex] = order[i];
59                 order[i] = temp;
60             }
61             for(int i=0;i<52;i++)
62             {
63                 if(order[i]>=0&&order[i]<=25)
64                 {
65                     double j = order[i]+65;
66                     char e = (char)j;
67                     System.out.print(e+":");
68                 }else{
69                     double j = order[i]+97-26;
70                     char e = (char)j;
71                     System.out.print(e+":");
72                 }
73                 double x = result[order[i]]*100;
74                 System.out.println(df.format(x)+"%");
75             }
76
77         } catch (Exception e) {
78             // TODO: handle exception
79         }
80     }
81
82 }