本程序有两个文件构成，bigintadd.h和bigintadd.cpp，bigintadd.h定义了大整数加法方法，bigintadd.cpp定义了输出语句。-This program has two documents constitute, bigintadd.h and bigintadd.cpp, bigintadd.h defines a large integer addition method, bigintadd.cpp defines the output statement