如何计算此 C++ 代码中的正确答案

Question

我正在尝试运行这段代码，它将计算用户做出的正确答案的数量。

但我不知道怎么做。我想我应该使用 if 或嵌套的 if 来做到这一点。我该怎么做？

这将要求用户输入他们的正确答案 A、B、C 或 D。然后我想递增 n：

#include <stdio.h>
#include <conio.h>

#define p printf
#define s scanf

main () {
    int Ttl;
    char Ln, Mi, Fn,
         A1,   A2,  A3,  A4,  A5,  A6,  A7,  A8,  A9, A10,
         A11, A12, A13, A14, A15, A16, A17, A18, A19, A20;

    clrscr();

    p("\n)
    p("\n\nEnter your last name: ");
    s("%s", &Ln);
    p("\nEnter your middle initial: ");
    s("%s", &Mi);
    p("\nEnter your first name: ");
    s("%s", &Fn);
    p("\nType the corresponding letter to each question.");
    p("\n1.) Shortcut for'New Line'");
    p("\n  A. Ctrl + R          C. Ctrl + M ");
    p("\n  B. Ctrl + QC          D. Ctrl + KC ");
    p("\nAnswer: ");
    s("%s", A1);
    p("\n2.) Shortcut for'Up Arrow Key'");
    p("\n  A. Ctrl + Z          C. Ctrl + X ");
    p("\n  B. Ctrl + QC          D. Ctrl + E ");
    p("\nAnswer: ");
    s("%s", A2);
    p("\n3.) Shortcut for'Down Arrow Key'");
    p("\n  A. Ctrl + X          C. Ctrl + E ");
    p("\n  B. Ctrl + C          D. Ctrl + R ");
    p("\nAnswer: ");
    s("%s", A3);
    p("\n4.) Shortcut for'Scroll Down'");
    p("\n  A. Ctrl + X          C. Ctrl + R ");
    p("\n  B. Ctrl + E          D. Ctrl + Z ");
    p("\nAnswer: ");
    s("%s", A4);
    p("\n5.) Shortcut for'Page Up'");
    p("\n  A. Ctrl + K          C. Ctrl + R ");
    p("\n  B. Ctrl + Q          D. Ctrl + C ");
    p("\nAnswer: ");
    s("%s", A5);
    p("\n6.) Shortcut for'Page Down'");
    p("\n  A. Ctrl + Q          C. Ctrl + K ");
    p("\n  B. Ctrl + C          D. Ctrl + Z ");
    p("\nAnswer: ");
    s("%s", A6);
    p("\n7.) Shortcut for'Top of a File'");
    p("\n  A. Ctrl + KY          C. Ctrl + KC  ");
    p("\n  B. Ctrl + QC          D. Ctrl + QR ");
    p("\nAnswer: ");
    s("%s", A7);
    p("\n8.) Shortcut for'Bottom of a File'");
    p("\n  A. Ctrl + QC          C. Ctrl + KY ");
    p("\n  B. Ctrl + QS          D. Ctrl + KC ");
    p("\nAnswer: ");
    s("%s", A8);
    p("\n9.) Shortcut for'Copy Block'");
    p("\n  A. Ctrl + QY          C. Ctrl + KC ");
    p("\n  B. Ctrl + KY          D. Ctrl + QC ");
    p("\nAnswer: ");
    s("%s", A9);
    p("\n10.) Shortcut for'Delete Block'");
    p("\n  A. Ctrl + QR          C. Ctrl + QC ");
    p("\n  B. Ctrl + KC          D. Ctrl + KY ");
    p("\nAnswer: ");
    s("%s", A10);
    p("\n11.) Hot Keys Command 'Saves the file currently being edited'");
    p("\n  A. F6          C. F2 ");
    p("\n  B. F4          D. F9 ");
    p("\nAnswer: ");
    s("%s", A11);
    p("\n12.) Hot Keys Command'Loads a File'");
    p("\n  A. F7          C. F1");
    p("\n  B. F3          D. F8");
    p("\nAnswer: ");
    s("%s", A12);
    p("\n13.) Hot Keys Command'Compiles and link the program'");
    p("\n  A. F4          C. F3 ");
    p("\n  B. F2          D. F9 ");
    p("\nAnswer: ");
    s("%s", A13);
    p("\n14.) Hot Keys Command'Compiles file to .obj file'");
    p("\n  A. Alt + F9          C. Alt + F5 ");
    p("\n  B. Alt + F2          D. Alt + F7 ");
    p("\nAnswer: ");
    s("%s", A14);
    p("\n15.) Hot Keys Command'Next error'");
    p("\n  A. Alt + F4          C. Alt + F9 ");
    p("\n  B. Alt + F7          D. Alt + F8 ");
    p("\nAnswer: ");
    s("%s", A15);
    p("\n16.) Hot Keys Command'Previous error'");
    p("\n  A. Alt + F7          C. Alt + F9 ");
    p("\n  B. Alt + F3          D. Alt + F1 ");
    p("\nAnswer: ");
    s("%s", A16);
    p("\n17.) Hot Keys Command'Activates the file menu'");
    p("\n  A. Alt + E           C. Alt + C ");
    p("\n  B. Alt + F          D. Alt + O ");
    p("\nAnswer: ");
    s("%s", A17);
    p("\n18.) Hot Keys Command'Quit the Turbo C program'");
    p("\n  A. Alt + D          C. Alt + P ");
    p("\n  B. Alt + C          D. Alt + X ");
    p("\nAnswer: ");
    s("%s", A18);
    p("\n19.) Hot Keys Command'Runs the program'");
    p("\n  A. Ctrl + F3          C. Ctrl + F2 ");
    p("\n  B. Ctrl + F5          D. Ctrl + F9 ");
    p("\nAnswer: ");
    s("%s", A19);
    p("\n20.) Hot Keys Command'Switches between windows'");
    p("\n  A. F2          C. F6 ");
    p("\n  B. F4          D. F8 ");
    p("\nAnswer: ");
    s("%s", A20);
    p("Thank you for answering the following question");
    p("\nCalculating correct answers. Please wait...");
    delay(5000);
    p("\nYour total correct answer is: ");
    p("\n\t\tEnd of the Program");

    getche();
}

Answer 1

我建议使用有序映射数据结构。这由 key 和 value 对组成。如果您使用的是标准库，它有一个有序的地图数据结构，该结构与用于数据存储的底层 red-black tree 一起运行。

对于您的示例，您可以简单地使用问题编号（或任何组合）作为键，并将结果答案作为值。

因此，要检查学生是否正确回答了问题，您需要输入问题键进行查找，然后 return 输入正确的答案值。然后您可以将此值与所选答案进行比较。

Here is the documentation for the standard library ordered map data structure

地图可以很容易地预先填充您布置的数据。只需创建一个函数来解析您的文本文件并创建一组 key/value 对插入到地图中。这是程序员非常普遍的使用模式。许多软件工程公司添加了诸如 PopulateValuesFromFile(...) 之类的函数来为数据结构填充数据。它还使代码看起来更清晰，因为它没有填充大量硬编码字符串。

Answer 2

这是一种使用结构数组的方法。这样你就可以在同一个地方保留尽可能多的参数（与问题相关）：

#include <stdio.h>


typedef struct {
    const char *question;
    int correct_answer;
    int given_answer;
} question_t;


int main() {

    question_t questions[] = {
        {"how many wings does bird have?\n1) 55\t3) 3\n2) 5\t4) 2", 4},
        {"how many heads does frog have?\n1) 55\t3) 3\n2) 1\t4) 2", 2},
        {NULL},
    };
    
    int number_of_corrent_unswers = 0;
    for(int i=0; questions[i].question != NULL; i++) {
        puts(questions[i].question);
        scanf("%d", &questions[i].given_answer);
        if(questions[i].given_answer == questions[i].correct_answer) {
            number_of_corrent_unswers++;
        }
    }
    printf("number of correct answers: %d\n", number_of_corrent_unswers);
    return 0;
}

如何计算此 C++ 代码中的正确答案

How to count the correct answers in this C++ code

c++

turbo-c++