画柱状图Java

样例输入：
THE QUICK BROWN FOX JUMPED OVER THE LAZY DOG.
THIS IS AN EXAMPLE TO TEST FOR YOUR
HISTOGRAM PROGRAM.
HELLO!
样例输出：

*

*

* *

* * * *

* * * *

* * * * * *

* * * * * * * * * *

* * * * * * * * * * * * *

* * * * * * * * * * * * * * * * * *

* * * * * * * * * * * * * * * * * * * * * * * * * *

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

题目的意思是从命令行输入一个大写的字符串，求一个字符出现的频率，画出来。

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;

public class Main {

public static void main(String[] args) throws NumberFormatException,
IOException {
BufferedReader read = new BufferedReader(new InputStreamReader(
System.in));
int[] a = new int[26];
int tt;
for (int i = 0; i < 4; i++) {
String str = read.readLine();
for (int j = 0; j < str.length(); j++) {
tt = str.charAt(j) - 'A';
if (tt >= 0 && tt <= 25) {
a[tt]++;
}
}
}
int max = 0;
for (int i = 0; i < 26; i++) {
if (a[i] > max) {
max = a[i];
}
}
char[][] c = new char[max + 1][51];
for (int i = 0; i < max + 1; i++) {
Arrays.fill(c[i], ' ');
}
for (int i = 0; i < 26; i++) {
int h = a[i];
for (int j = 0; j < h; j++) {
c[max - 1 - j][i * 2] = '*';
}
}
for (int i = 0; i < 26; i++) {
c[max][i * 2] = (char) ('A' + i);
}
for (int i = 0; i < max + 1; i++) {
String str = String.valueOf(c[i]);
while (str.endsWith(" ")) {
str = str.substring(0, str.length() - 1);
}
System.out.println(str);
}
}