9vi.cpp

C/C++程序设计导论（第二版）》程序源文件

// InDictionary()  Accept an istream file var. for a disk file
//   and a string var. for a word. Return true if the word is
//   found in the dictionary disk file (else false).
//   ASSUMPTION: file has already been opened
//	IN: infile is file variable to an alphabetized lower-case dictionary
//	IN:	user_word is a lower-case word.

int InDictionary (ifstream& infile, string user_word)
{	int done = 0;					// loop completion flag
	int found = 0;					// word-found flag
	string dict_word;					// var for dictionary words
	while (!done)
	{	if (infile >> dict_word)				// get next dict. word...
		{	if (user_word == dict_word)			// do words match?
			{	done = 1;
				found = 1;
			}
			else if (user_word < dict_word)
				done = 1;			// searched too far.
		}
		else
			done = 1;			// end of file.
	}
	return (found);				
}