public class Count
extends Object
Compilation: javac Count.java
Execution: java Count alpha < input.txt
Create an alphabet specified on the command line, read in a
sequence of characters over that alphabet (ignoring characters
not in the alphabet), computes the frequency of occurrence of
each character, and print out the results.
% java Count ABCDR < abra.txt
A 5
B 2
C 1
D 1
R 2
% java Count 0123456789 < pi.txt
0 99959
1 99757
2 100026
3 100230
4 100230
5 100359
6 99548
7 99800
8 99985
9 100106