这个是递归计算实现类文档，是关于雨流记数的递归算法。-recursion

输入一个字符串，扫描该字符串，按数字、字母和特殊字符3类，把字符分类输出到屏幕，并计算其中数字字符的和，把求得的和以十进制数的形式输出到屏幕。-Enter a string, the string scanning, numbers, letters and special characters are three types of character output to the screen, and calculate one of the numeric characters, to ob