C ++-使用数组

Question

The Motor vehicle Administration has asked you to write a program that grades the written portion of the Driver's License exam. The Exam has a 20 multiple choice questions with the answers for the questions 1…20 respectively shown in the list below;

A   B   D   A   B   B   B   C   C   D   A   C   C   C   D   A   B   D   D   B

It is assumed that a total of 10 students take the exam each day. Your program should store the correct answer shown above in an Array. It should then ask each student's answer for the 20 questions and the answers should be stored in another array. After the answers have been entered, the program should display a message indicating whether a student passed or failed the exam.(A student must correctly answer 18 out of 20 questions to pass the exam).It should then display the total number of correctly answered questions and the total number of incorrectly answered questions by each student. Your program should also display the percent of students who passed the test in a given day.

#include <iostream>
using namespace std;

int main()
{
    // Declare variables and constants
    int correctAnswers = 0;
    const int QUESTIONS = 20;
    char answers[QUESTIONS] = {'A', 'B', 'D', 'A', 'B', 'B', 'B', 'C', 'C',  'D', 'A', 'C', 'C', 'C', 'D', 'A', 'B', 'D', 'D', 'B'};

    for(int count = 0; count < QUESTIONS; count++)
    {
        cout << "Please enter your answer for Question " << (count + 1) << endl;
        cin >> answers;
    }
    if(answers[0] == 'A')
    {
        correctAnswers++;
    }
    else if(answers[1] = 'B')
    {
        correctAnswers++;
    }

    return 0;
}    

So I have begun to write this code for the problem statement listed above. This is what I have so far. I started making if statements for each of the answers, and if they inputted the correct answer, the result will add 1 to the counter. My question is, Is there a better way to get the users answers and check to see if they are correct, or is what I am doing now, the best way to do it?

Answer 1

In the specification you must store the list of correct answers in an array. the answer of each student must be too saved in an array. After getting the answers of a student you can iterate over the answers and compare them with the expected answers.

  char correct_answers[QUESTIONS] = {'A', 'B', 'D','A','B', 'B','B','C','C', 'D','A','C' ,'C' , 'C' ,'D' ,'A' ,'B','D', 'D',  'B'};
    char answers[QUESTIONS];
    for(int count = 0; count < QUESTIONS; count++) {
        cout << "Please enter your answer for Question " << (count + 1) << endl;
        cin >> (answers+count);
    }

    for(int count = 0; count < QUESTIONS; count++) {
        if(answers[count] == correct_answers[count]) {
            correctAnswers++;
        }
    }

Answer 2

Lets see.. you want to cin on something else, not answers because then your overwriting what you set as the Answer Key!

When you look you check answers[count] == inputValue from cin.

basically.. some pseudo code..

char inputValue;

loop ..
    cin << inputValue;
    answers[count] == inputValue  ...  
        Then ++correctAnswer ...