题目要求：
输出某个英文文本文件中 26 字母出现的频率，由高到低排列，并显示字母出现的百分比，精确到小数点后面两位。
源码：
package demo;
import java.io.File;
import java.io.InputStreamReader;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileReader;
import java.util.Arrays;
import java.util.List;
import java.util.StringTokenizer;
import java.io.FileWriter;
public class Demo {
static String[] save = new String[50000];
static float[] num1 = new float[26];
static float[] num2 = new float[26];
static float[] num3 = new float[52];
static char zimu[]={\'A\',\'B\',\'C\',\'D\',\'E\',\'F\',\'G\',\'H\',\'I\',\'J\',\'K\',\'L\',\'M\',\'N\',\'O\',\'P\',\'Q\',\'R\',\'S\',\'T\',\'U\',\'V\',\'W\',\'X\',\'Y\',\'Z\',\'a\',\'b\',\'c\',\'d\',\'e\',\'f\',\'g\',\'h\',\'i\',\'j\',\'k\',\'l\',\'m\',\'n\',\'o\',\'p\',\'q\',\'r\',\'s\',\'t\',\'u\',\'v\',\'w\',\'x\',\'y\',\'z\'};
static int i = 0;
public static void main(String args[]) {
try {
System.out.println(System.in);
import java.io.InputStreamReader;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileReader;
import java.util.Arrays;
import java.util.List;
import java.util.StringTokenizer;
import java.io.FileWriter;
public class Demo {
static String[] save = new String[50000];
static float[] num1 = new float[26];
static float[] num2 = new float[26];
static float[] num3 = new float[52];
static char zimu[]={\'A\',\'B\',\'C\',\'D\',\'E\',\'F\',\'G\',\'H\',\'I\',\'J\',\'K\',\'L\',\'M\',\'N\',\'O\',\'P\',\'Q\',\'R\',\'S\',\'T\',\'U\',\'V\',\'W\',\'X\',\'Y\',\'Z\',\'a\',\'b\',\'c\',\'d\',\'e\',\'f\',\'g\',\'h\',\'i\',\'j\',\'k\',\'l\',\'m\',\'n\',\'o\',\'p\',\'q\',\'r\',\'s\',\'t\',\'u\',\'v\',\'w\',\'x\',\'y\',\'z\'};
static int i = 0;
public static void main(String args[]) {
try {
System.out.println(System.in);
FileReader fileReader = new FileReader("C:\\Users\\dell\\Documents\\Tencent Files\\2436124704\\FileRecv\\Harry Potter and the Sorcerer\'s Stone.txt");
BufferedReader buf = new BufferedReader(fileReader);
String bufToString = "";
String readLine = "";
String[] myArray = new String[50000]; //100：这个值你自己定义，但不宜过大，要根据你文件的大小了，或者文件的行数
while((readLine = buf.readLine()) != null){
myArray[i] = readLine;
save[i]=myArray[i];
i++;
}
}
catch (Exception e) {
// e.printStackTrace();
System.out.println("连不上");
}
int length;
int j=0;
int t=0;
for(t=0;t<i;++t)
{
char ss[] = save[t].toCharArray();
BufferedReader buf = new BufferedReader(fileReader);
String bufToString = "";
String readLine = "";
String[] myArray = new String[50000]; //100：这个值你自己定义，但不宜过大，要根据你文件的大小了，或者文件的行数
while((readLine = buf.readLine()) != null){
myArray[i] = readLine;
save[i]=myArray[i];
i++;
}
}
catch (Exception e) {
// e.printStackTrace();
System.out.println("连不上");
}
int length;
int j=0;
int t=0;
for(t=0;t<i;++t)
{
char ss[] = save[t].toCharArray();
for(j=0;j<ss.length;++j)
{
if(ss[j]>=\'A\'&&ss[j]<=\'Z\')
{int k=(int)ss[j];
num1[k-65]++;
}
else if(ss[j]>=\'a\'&&ss[j]<=\'z\')
{int k=(int)ss[j];
num2[k-97]++;
}
}
}
{
if(ss[j]>=\'A\'&&ss[j]<=\'Z\')
{int k=(int)ss[j];
num1[k-65]++;
}
else if(ss[j]>=\'a\'&&ss[j]<=\'z\')
{int k=(int)ss[j];
num2[k-97]++;
}
}
}
/*for(j=0;j<26;++j)
{System.out.println(num2[j]);
}*/
float all=0;
for(j=0;j<26;++j)
{
all+=num1[j];
all+=num2[j];
}
for(j=0;j<26;++j)
{
num1[j]=num1[j]/all*100;
num2[j]=num2[j]/all*100;
}
for(j=0;j<26;++j)
{
num3[j]=num1[j];
num3[j+26]=num2[j];
}
for(j=0;j<52;++j)
{float[] max = new float[26];
int[] flag = new int[52];
int p=0;
for(t=0;t<52;++t)
{
if(num3[t]>max[0])
{
flag[0]=t;
max[0]=num3[t];
}
/*else if(num3[t]==max[0])
{
p++;
flag[p]=t;
max[p]=num3[t];
}*/
}
/*for(int k=0;k<p;++k)
{
System.out.println(zimu[flag[p]]+":"+max[p]+"%");
}*/
System.out.print(zimu[flag[p]]+":");
float fff=(float)(Math.round(max[p]*100))/100;
System.out.println(fff+"%");
num3[flag[p]]=0;
}
}
}
}