task_cpp

Please submit the complete C++ source code for a program that counts the number of distinct unique words read from the standard input. For example, given the input "a horse and a dog" the program must output "4" (the word 'a' appears twice but only accounts for one distinct unique occurrence). The input text is guaranteed to contain only 'a'..'z' and space characters in ASCII encoding. The program should be able to handle large inputs (e.g. 32 GiB) You can assume that all unique words fit into memory when using the data structure of your choice.