A: the statistical frequency of occurrence of letters in the file (case sensitive) is given, and pressing the reverse output frequency of occurrence
Ideas: 1, the contents of the file into the StringBuffer;
2, the content read is divided;
3, through the array, which is placed in a TreeMap <String, Integer> in;
4, its calculated frequency sorting;
package file; import java.io.BufferedReader; import java.io.FileReader; import java.io.IOException; import java.math.BigInteger; import java.text.DecimalFormat; import java.util.ArrayList; import java.util.Comparator; import java.util.TreeMap; import java.util.TreeSet; public class zimupaixu { public static void main(String [] args) throws IOException { //读取文件 BufferedReader br=new BufferedReader(new FileReader("F:\\\\备用\\\\english.txt")); TreeMap<Character,Integer> tm=new TreeMap<>();//打开哈希表 int key; while((key=br.read())!=-1) { if((key>='A'&&key<='Z')||(key>'a'&&key<='z')) { tm.put (( char ) Key, tm.containsKey (( char ) Key) tm.get ((? char ) Key) +1: 1); // cumulative number of different letters appear } } br.close(); int max=0; int sum=0; int t=0; for(Character k: tm.keySet()) { sum=sum+tm.get(k); } TreeSet<Character> ts=new TreeSet<>(new Comparator<Character>() { public int compare(Character a,Character b) { int num=tm.get(a)-tm.get(b); return num==0?1:(-num); } }); for(Character k: tm.keySet()) { ts.add(k); } DecimalFormat df = new DecimalFormat("0.00%"); for (Character c : ts) { float bai=(float)tm.get(c)/sum; System.out.println (C + "" + "appears percentage" + "" + df.format (Bai)); } //System.out.println(sum); }}
Second, the first N English word most commonly occurring single output file
Ideas: 1, from beginning to end through the file, read from a file to traverse every word.
2, the traverse to put words in TreeHasp, and count the number of times the word appears.
3, defines how many words a global variable N control output
4, the number of cycles for all the words are compared to obtain the largest number of occurrences, cycle N times.
package file; import java.io.BufferedReader; import java.io.File; import java.io.FileReader; import java.io.IOException; import java.util.*; public class danci { class Word//定义单词类 { Value String; // particular word int COUNT; // number appearing Word Next; // the word chain together public Word (String value, int geshu) // parameterized constructor { the this .Value = value; the this . = COUNT geshu; next=null; } public Word () // constructor { the this .Value = "" ; the this .count = 0 ; next=null; } } /* * Read the file and directory names in the specified path */ public void getFileList() throws IOException { BufferedReader br=new BufferedReader(new FileReader("F:\\备用\\english.txt")); TreeMap<Character,Integer> hm=new TreeMap<>(); int key; while((key=br.read())!=-1) { Word Word = new new Word (); // word chain head Word lian, xin; STR String = "" ; char [] = C new new char [. 1]; // read one letter int B = 0 ; Boolean exist = to false ; // determines whether there is a word in the word chain, the while ((B = br.read (C)) = -!. 1) // read letters { // divided IF (String.valueOf (C) .equals ( "\ R & lt") || String.valueOf (C) .equals ( "\ n ") || String.valueOf (c) .equals (" ") || String.valueOf (c) .equals (", ") || String.valueOf (c) .equals (". ") || String .valueOf (c) .equals ( "\ " ") || String.valueOf (c) .equals ("'")) { lian=word; while(lian!=null) { IF (lian.value.equalsIgnoreCase (STR)) // total number of different words { lian.count++;exist=true; break; } else { lian=lian.next; } } IF (== exist to false ) // If not, the word is added in the chain { xin=new Word(str,1); xin.next=word.next; word.next=xin; str=""; } else { exist=false; str=""; } } else { str+=String.valueOf(c); } } System.out.print ( "the number of the first N longest appearance of the word:" ); Scanner scan=new Scanner(System.in); int N=scan.nextInt(); System.out.println(""); for(int i=1;i<=N;i++) { // The N output corresponding to the input words, and the number thereof XIN = new new Word ( "", 0 ); lian=word.next; while(lian!=null) { if(lian.count>xin.count) { XIN = Lian; } lian=lian.next; } System.out.println(+i+" :"+xin.value+" "+xin.count); Lian = Word; // delete the word chain in the most number of words the while (lian.next =! null ) { if(lian.next.value.equalsIgnoreCase(xin.value)) { lian.next=lian.next.next; break; } lian=lian.next; } } } } public static void main(String[] args) throws IOException { RF danci = new new danci (); rf.getFileList(); }
Code Screenshot:
Three: the specified file directory, but all subdirectories recursively directory, the number of execution statistics for each file and the percentage of words
package file; import java.io.BufferedReader; import java.io.File; import java.io.FileNotFoundException; import java.io.FileReader; import java.io.IOException; import java.text.DecimalFormat; import java.util.Comparator; import java.util.Scanner; import java.util.TreeMap; import java.util.TreeSet; public class dancichachong { //F:\\\\\\\\备用\\\\\\\\english.txt public static void main(String[] args) throws IOException { System.out.println ( "Please enter the path to traverse file:" ); Scanner sc=new Scanner(System.in); File file=getfile(); bianli (file); System.out.println ( "Please select the document you want to query" ); String name=sc.next(); display(name); } public static void bianli (File File) { File [] yue=file.listFiles(); for(File fi:yue) { if(!fi.isDirectory()) { if(fi.getName().endsWith(".txt")) { System.out.println(fi.getPath()); } } else { bianli (fi); } } } public static void display(String path) throws IOException { Scanner sc=new Scanner (System.in); BufferedReader br=new BufferedReader(new FileReader(path)); int c; TreeMap<String,Integer> tm=new TreeMap<>(); String line; int kt=0; while((line=br.readLine())!=null) { String [] str=line.split("[^a-zA-Z]"); for(int i=0;i<str.length;i++) { if(!str[i].equals("")) { tm.put(str[i],tm.containsKey(str[i])?tm.get(str[i])+1:1);} } } br.close(); int max=0; int sum=0; int t=0; for(String k: tm.keySet()) { sum=sum+tm.get(k); if(max<=tm.get(k)) { max=tm.get(k); } } TreeSet<String> ts=new TreeSet<>(new Comparator<String>() { public int compare(String a,String b) { int num=tm.get(a)-tm.get(b); return num==0?1:(-num); } }); for(String k: tm.keySet()) { ts.add(k); } DecimalFormat df = new DecimalFormat("0.00%"); System.out.println ( "Please enter the number to query" ); int COUNT = sc.nextInt (); int Q = 0, I =. 1 ; for (String S: TS) { if(q==count) { break; } else { q++; float bai=(float)tm.get(s)/sum; System.out.println(i+" "+s+" "+tm.get(s)+" "+df.format(bai)); } i++; } } public static File getfile() { Scanner sc=new Scanner(System.in); while(true) { String line=sc.nextLine(); File kk=new File(line); if(!kk.exists()) { System.out.println ( "do not enter a folder, please re-enter" ); } else if(kk.isFile()) { System.out.println ( "Enter the file path, please re-enter" ); } else { return kk; } } } }
Code test shots:
