Question

我在编写此代码时遇到了for循环问题。一切都运行正常，除了它没有捕获我的字符串数组中的第4行的值（“Jill”，“Jason”，“Jim”。）

我很确定问题发生在我的'Initialize'函数定义中，因为我的vector没有捕获最终ID和团队成员最终列表的值。作为参考，输出很好，直到最后的TeamV元素。我已经尝试过搞乱这些指数了，但我已经碰到了一堵砖墙。提前致谢。

    #include <vector>
    #include <iomanip>
    #include <iostream>
    #include <string>

    using namespace std;

    const int NUM_TEAMS = 4;
    const int NUM_MEMBERS = 3;

    struct TeamS {
        int id;
        string m[NUM_MEMBERS];

    }TeamV, tempTeam;

    void Initialize(vector <TeamS> & TeamV, const int id[],
        const string m[][NUM_MEMBERS], int arraySize);

    void printList(const vector <TeamS> & TeamV);

    int main()
    {
        const int ID[NUM_TEAMS] = { 123, 321, 456, 789 };

        const string MEMBERS[NUM_TEAMS][NUM_MEMBERS] =
        {
        { "Sarah", "Joe", "John" },
        { "Chris", "Kevin", "James" },
        { "Tom", "Kim", "Emily" },
        { "Jill", "Jason", "Jim" }
        };

        vector<TeamS> TeamV;

        Initialize(TeamV, ID, MEMBERS, NUM_TEAMS);
        cout << TeamV[3].m[1];
        printList(TeamV);

        // not working on my installation at home  -> system("pause");
        cin.get();



    }

    void Initialize(vector<TeamS>& TeamV, const int id[], const string m[][NUM_MEMBERS], int arraySize)
    {
        //Resizes a TeamS vector and then modifies it's values to match the information provided
        TeamV.resize(arraySize+1);

        //iterate through teams
        for (int i = 0; i < arraySize+1; i++)
        {

            TeamV[i].id = id[i];

            //iterate through members of teams
            for (int j = 0; j < NUM_MEMBERS; j++)
            {
                TeamV[i].m[j] = m[i][j];
            }

        }
    }


    void printList(const vector<TeamS>& TeamV)
    {
        cout << "**** Team List ****\n\n";
        int teamVSize = TeamV.size();

        for (int i = 0; i < teamVSize; i++)
        {
            cout << "Information for team " + to_string(i) << endl;
            cout << "ID:\t" << TeamV[i].id << "\t";

            for (int j = 0; j < NUM_MEMBERS; j++)
            {
                cout << TeamV[i].m[j] << "\t";
            }

            cout << endl;
        }
}

Answer 1

您的for循环超出了数组的范围。摆脱+1

for (int i = 0; i < arraySize; i++)

Answer 2

你传入一个包含4行的2D数组，但在你的initialise（）函数中你循环了5次：

public Comparable[] common(Comparable[] a, Comparable[] b) {
    // List is more flexible, but the toArray at the end is a bit costly. You can probably figure a better way of doing this.
    List<Comparable> res = new ArrayList<>();
    int indexA = 0;
    int indexB = 0;
    while (indexA < a.length && indexB < b.length) {
        // Exercice for the reader: replace with compareTo calls
        if (a[indexA] == b[indexB]) {
            // Common item!
            res.add(a[indexA]);
            indexA++;
            indexB++;
        } else if (a[indexA] < b[indexB]) {
            // item in A is smaller, try the next
            indexA++;
        } else {
            indexB++;
        }
    }
    return res.toArray(new Comparable[0]);
}

零索引是第一个，索引i = 4表示第5行，你超出了你创建的数组，我得到了一个std :: bad_alloc异常。

如果你从＆＃34; arraySize + 1＆＃34;中省略了+ 1;它工作正常。

顺便说一下，现在的方式是，它正确地填充了4行，直到它抛出bad_alloc异常，所以我不明白为什么你说它排除了第4行。

我的for-loop如何搞乱？

2 个答案: