1统计字母出现的概率(不分大小写)
import java.io.BufferedReader; import java.io.FileReader; import java.io.IOException; import java.text.DecimalFormat; import java.text.NumberFormat; public class a { private static NumberFormat nf = new DecimalFormat("0.00"); public static void main(String[] args) throws IOException { BufferedReader br = new BufferedReader(new FileReader("f:/piao.txt")); StringBuilder sb = new StringBuilder(); while (true) { String line = br.readLine(); if (line == null) break; sb.append(line); } br.close(); int[] characters = new int[128]; for (byte bt : sb.toString().getBytes()) if (bt > 0 && bt < 128) characters[bt]++; int totalCount = 0; for (int i = 'a'; i <= 'z'; i++) { totalCount += (characters[i] + characters[i - 32]); } double c; for (int i = 'a'; i <= 'z'; i++) { c=(double)(Math.round((characters[i] + characters[i - 32]) * 100 / totalCount)/100.0); System.out.print((char) i + "=" + (characters[i] + characters[i - 32]) + "(" +c + "),"); } } }
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2统计单词出现的次数
import java.io.BufferedReader;
import java.io.FileReader;
import java.util.*;
public class b {
public static void main(String [] args) throws Exception {
BufferedReader br = new BufferedReader(new FileReader("f:/飘c1.txt"));
StringBuffer sb = new StringBuffer();
String text =null;
while ((text=br.readLine())!= null){
sb.append(text);// 将读取出的字符追加到stringbuffer中
}
br.close(); // 关闭读入流
String str = sb.toString().toLowerCase(); // 将stringBuffer转为字符并转换为小写
String[] words = str.split("[^(a-zA-Z)]+"); // 非单词的字符来分割，得到所有单词
Map<String ,Integer> map = new HashMap<String, Integer>() ;
for(String word :words){
if(map.get(word)==null ){ // 若不存在说明是第一次，则加入到map,出现次数为1
map.put(word,1);
}else
{
map.put(word,map.get(word)+1); // 若存在，次数累加1
}
}
// 排序
List<Map.Entry<String ,Integer>> list = new ArrayList<Map.Entry<String,Integer>>(map.entrySet());
Comparator<Map.Entry<String,Integer>> comparator = new Comparator<Map.Entry<String, Integer>>() {
public int compare(Map.Entry<String, Integer> left, Map.Entry<String, Integer> right) {
return (left.getValue().compareTo(right.getValue()));
}
};
// 集合默认升序升序
Collections.sort(list,comparator);
for(int i=0;i<list.size();i++){// 由高到低输出
System.out.println(list.get(list.size()-i-1).getKey() +":"+list.get(list.size()-i-1).getValue());
}
}
}
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3去除无用词
public class English_word {
public static void main(String[] args) throws FileNotFoundException {
File file = new File("D:\Englis_letter.txt");// 读取文件
String words[] = new String [100000];
int out_words[] = new int [100000];
if (!file.exists()) {// 如果文件打不开或不存在则提示错误
System.out.println("文件不存在");
return;
}
Scanner x = new Scanner(file);
HashMap<String, Integer> hashMap = new HashMap<String, Integer>();
while (x.hasNextLine()) {
String line = x.nextLine();
String[] lineWords = line.split("[\s+ ”“();,.?!
]");
Set<String> wordSet = hashMap.keySet();
for (int i = 0; i < lineWords.length; i++) {
if (wordSet.contains(lineWords[i])) {
Integer number = hashMap.get(lineWords[i]);
number++;
hashMap.put(lineWords[i], number);
} else {
hashMap.put(lineWords[i], 1);
}
}
}
Iterator<String> iterator = hashMap.keySet().iterator();
int max = 0,i=0;
while (iterator.hasNext()) {
String word = iterator.next();
if(!"".equals(word)&&word!=null&&!"a".equals(word)&&!"the".equals(word)&&!" ".equals(word)) {
System.out.println(word);
words[i]=word;
out_words[i]=hashMap.get(word);
i++;
}
}
int change=0;
String change_word=null;
for(int j=0;j<=i;j++)
{
for(int k=j;k<=i;k++)
{
if(out_words[k]>out_words[j])
{
change=out_words[j];
change_word=words[j];
out_words[j]=out_words[k];
words[j]=words[k];
out_words[k]=change;
words[k]=change_word;
}
}
}
Scanner scan = new Scanner(System.in);
int ms = scan.nextInt();
for(int j=0;j<ms;j++)
{
System.out.println(words[j]+" 出现次数:"+out_words[j]);
}
}
4遍历文件统计
public class test { static String words[] = new String [100000]; static int out_words[] = new int [100000]; static int i=0; static HashMap<String, Integer> hashMap = new HashMap<String, Integer>(); public static void English_words(File ms) throws FileNotFoundException { File file = new File(ms.toString());// 读取文件 if (!file.exists()) {// 如果文件打不开或不存在则提示错误 System.out.println("文件不存在"); return; } Scanner x = new Scanner(file); while (x.hasNextLine()) { String line = x.nextLine(); String[] lineWords = line.split("[\s+ ”“();,.?! ]"); Set<String> wordSet = hashMap.keySet(); for (int i = 0; i < lineWords.length; i++) { if (wordSet.contains(lineWords[i])) { Integer number = hashMap.get(lineWords[i]); number++; hashMap.put(lineWords[i], number); } else { hashMap.put(lineWords[i], 1); } } } } public static void main(String[] args) throws FileNotFoundException { String path = "d:/"; File file = new File(path); File[] tempList = file.listFiles(); for (int i = 0; i < tempList.length; i++) { if (tempList[i].toString().endsWith("txt")) { System.out.println("文 件：" + tempList[i]); English_words(tempList[i]); } } Iterator<String> iterator = hashMap.keySet().iterator(); int max = 0; while (iterator.hasNext()) { String word = iterator.next(); if(!"".equals(word)&&word!=null&&!"a".equals(word)&&!"the".equals(word)&&!" ".equals(word)) { words[i]=word; out_words[i]=hashMap.get(word); i++; } } int change=0; String change_word=null; for(int j=0;j<=i;j++) { for(int k=j;k<=i;k++) { if(out_words[k]>out_words[j]) { change=out_words[j]; change_word=words[j]; out_words[j]=out_words[k]; words[j]=words[k]; out_words[k]=change; words[k]=change_word; } } } Scanner scan = new Scanner(System.in); int ms = scan.nextInt(); for(int j=0;j<ms;j++) { System.out.println(words[j]+" 出现次数:"+out_words[j]); } } }