10i.cpp

C/C++程序设计导论（第二版）》程序源文件

// gradtest.cpp  Grade student quiz answers in file `students.txt' against
//   the key in disk file `key.txt'. Report each student's score and a class 
//   summary of the number correct for each question.
#include <iostream.h>
#include <fstream.h>
const int SIZE = 5;

void main ()
{	ifstream keyfile_in ("key.txt", ios::in);
	ifstream studentfile_in ("students.txt", ios::in);
	char answers[SIZE], thisanswer;
	int ans, summary[SIZE] = {0, 0, 0, 0, 0}, id, n, score;

for (n=0; n<SIZE; n++)
	keyfile_in >> answers[n];					// input answer key array

while (studentfile_in >> id)							// loop over students
{	 score = 0;					// assume a zero score
	for (ans=0; ans<SIZE; ans++)						// loop over answers
	{	studentfile_in >> thisanswer;					// get next answer
		if (thisanswer==answers[ans])   					// is it right?
		{	score++;					// if so, increase grade
			summary[ans]++;				// and tabulate
		}	
	}					// end of loop over answers (ans)
	cout << "student: "<< id <<"  score: " << score << endl;
}   						// end of loop over students (while)

cout << "	correct answers sumary for each question; ";
for (n=0; n<SIZE; n++)					
	cout <<summary[n] << " ";					// output summary table
}