在正确循环代码并平均循环时中断执行（主要停留在此）C++

Question

我已经放弃了这个任务，但我已经保存了旧代码，所以如果有什么可以挽救的，我会全力以赴。

我现在有一个 do while 循环，它会重复两个问题，就像用户输入的一样多，而且效果很好。但是我不知道如何将最终数字加在一起，甚至更不知道如何让它们正确平均，这样我就可以把它们变成一个百分比。

#include<iostream>
#include<iomanip>

using namespace std;

int main() 
{
    //declare variables
    int n = 0;
    int counter = 0;
    double score = 0.0;
    double total = 0.0;
    double avg = 0.0;
    double scoreTotal = 0.0;
    double totalTotal = 0.0;


    //Prompt user for number of assignments
    cout << "How many assignments are there? ";
    cin >> n;

    counter = 0;
    do
    { 
        counter++;

        //prompt user for score    */count up for each query*/
        cout << "What is the score for assignment number " << counter << "? ";
        cin >> score;

        //prompt user for totals         */count up for each total*/
        cout << "What is the total score available for assignment number " << counter << "? ";
        cin >> total;

    }
    while(counter < n);

    //calculate averages

    scoreTotal += score;
    totalTotal += total;

    avg = ((scoreTotal / totalTotal) * 100) / n; 

    //output how much it was out of and percent

    cout << "Your total is " << scoreTotal << " out of " << totalTotal << ", or " <<  avg << "%" << endl;

    return 0;
}

我只是猜测 avg 部分，但结果不正确，所以我知道那是错误的。

我的旧代码让它正确地结束循环周期，但它对新代码的影响很大，比如将计数器更改为仅偶数，并且它输出的提示比用户请求的提示高。

#include<iostream>

using namespace std;

int main() 
{

    float s;  // assignment score
    float t;  // total points worth
    float p;  // percentage     
    int n;

    //input the number of assignments
    cout << "How many assignments are there? ";
    cin >> n;

        for (int i=1; i <=n; i++)
        {
            //input the total points earned for assignment
            cout << "What is the score earned for this assignment? ";
            cin >> s;

            //input the number of points assignment is worth
            cout << "How many points was the assignment worth? ";
            cin >> t;

            //calculate percentage
            p = ((s / t) * 100) ;
            p += i;
        }


    //output score
    cout.setf(ios::fixed);
    cout.setf(ios::showpoint);
    cout.precision(2);
    cout << "Total score: " << p << "%"<< endl;

    return 0;
}

我的教科书也无济于事。它从解释 Do 和 Do While 循环跳到展示如何使用 For 循环，而没有任何关于它们的兼容性的解释。

任何帮助！谢谢！

Answer 1

你的代码有点乱，但我有点明白你的任务的要点。

根据您的标题，您似乎正在寻找用户输入的 X 个任务的总数。现在，您只跟踪用户输入的最后一个分数和总分。

例如。 分数 = 5，总分 = 10 - 下一次迭代 分数 = 7，总分 = 20 - 5 和 10 被淘汰。

您需要做的是使用数组来跟踪所有这些（这似乎超出了您的范围），因此我建议将它们全部加起来并跟踪累积分数和总分。为此，您只需添加

scoreTotal += score;
totalTotal += total;  // Terrible name sorry

+= 的意思是 scoreTotal = score + scoreTotal，它会记录累计总和。最后你所要做的就是 scoreTotal/totalTotal 来找到平均值。

Answer 2

最终代码如下：

#include<iostream>
#include<iomanip>

using namespace std;

int main() 
{
    //declare variables
    int n, counter;
    double score, total, scoreSum = 0, totalSum = 0, answer;


    //Prompt user for number of assignments
    cout << "How many exercises to input? ";
    cin >> n;

    counter = 0;
    do
        { 
        counter++;

        //prompt user for score    */count up for each query*/

        cout << "What is the score for exercise " << counter << "? ";
        cin >> score;

        //prompt user for totals         */count up for each total*/

        cout << "What is the total points possible for exercise " << counter << "? ";
        cin >> total;


        //calculate averages

        scoreSum += score;
        totalSum += total;

        answer = (scoreSum / totalSum) * 100; 

            }
        while ( counter < n);


    //output how much it was out of and percent

    cout << "Your total is " << scoreSum << " out of " << totalSum << ", or " << fixed << setprecision (2) << answer << "%" << endl;

    return 0;
}