在从键盘上输入字符时，只要是键盘上的字符任何字符都能接受，并能统计出输入的一串字符串中各个字符出现的次数，作为构建哈夫曼树时的各叶子结点的权值。

本程序同时具有译码功能

-Character input from the keyboard, as long as any of the characters in the character on the keyboard can be accepted, and the statistics of the number of occurrences of each character in a bunch of string input, as the building Huffman tree leaf node weights. The program also has a decoding function