Question

#include <iostream>

using namespace std;

int grade(char [][5], int);

int main()
{
    int tests, i,j;
    cout << "How many tests?"; cin >> tests;
    char answers[tests][5];
    cout << "What were the answers for all the tests (T/F)?";
    for (i=0;i<tests;i++)
        for (j=0;j<5;j++) cin >> answers[i][j];;
    int g[tests] = {grade(answers, tests)};

    for (i=1;i<=tests;i++)
    {
        cout << "\n   Test " << i << ": ";
        cout << g[i-1] << " out of 25";
    }
    cout << endl;

    return 0;
}

int grade(char ans[][5], int test)
{
    int k, l;
    int gr[test]={0};
    char sheet[5] = {'T', 'T', 'F', 'F', 'T'}; cout << sheet[1];
    for (k=0;k<test;k++)
            for (l=0;l<5;l++)
                    if (ans[k][l]==sheet[l]) gr[k]+= 5;;;

    return *gr;
}

我无法弄清楚为什么我的程序如此不一致。如果我输入T T F F T进行第一次测试，一切都很好，但如果我有任何错误答案＆＃34;对于第一次测试，我的g数组的值似乎总是为0。

有什么想法吗？谢谢！

Answer 1

这是问题所在。函数的返回值返回单个数字，然后将该单个数字分配给数组的所有值。所以，无论第一个考试成绩如何，所有成绩都是相同的。

数组之后的{}设置数组的初始值，并且只有一个值使得该值被赋值给数组的所有部分。

我的编译器不喜欢int g[tests]的语法，因为它期望tests是常量，所以我必须转换那些动态数组大小声明。下面的代码在Visual Studio 2017上按预期工作。试试这个。

#include <iostream>

using namespace std;

int* grade(char** ans, int test);

int main()
{
    int tests, i, j;
    cout << "How many tests?"; cin >> tests;

    char** answers = new char*[tests];
    for (int i=0;i<tests;i++)
        answers[i] = new char[5];

    cout << "What were the answers for all the tests (T/F)?";
    for (i = 0; i<tests; i++)
        for (j = 0; j<5; j++) cin >> answers[i][j];

    int* g = grade(answers, tests);

    for (i = 1; i <= tests; i++)
    {
        cout << "\n   Test " << i << ": ";
        cout << g[i - 1] << " out of 25";
    }
    cout << endl;

    for (int i = 0; i < tests; i++)
        delete[] answers[i];
    delete[] answers;
    delete[] g;

    system("pause");

    return 0;
}

int* grade(char** ans, int test)
{
    int k, l;
    int* gr = new int [test] {0};
    char sheet[5] = { 'T', 'T', 'F', 'F', 'T' }; 
    cout << sheet[1];
    for (k = 0; k<test; k++)
        for (l = 0; l<5; l++)
            if (ans[k][l] == sheet[l]) gr[k] += 5;;;

    return gr;
}

与数组不一致

1 个答案: