修改#include <fstream> #include <iostream> using namespace std; struct Student { char name[100]; int* scores; double avg; }; Student* Input(char* file, int& stuNum, int& hwNum) { ifstream in(file, ios::in); int itemNum; in >> stuNum >> hwNum >> itemNum; // 定义和初始化学生列表 Student* stuList = new Student[stuNum]; for (int i = 0; i < stuNum; i++) { stuList[i].scores = new int[hwNum]; for (int j = 0; j < hwNum; j++) stuList[i].scores[j] = 0; } // 读入数据 int k = 0; for (int i = 0; i < itemNum; i++) { char name[100]; int time, score; in >> name >> time >> score; int j; for ( j = 0; j < k; j++) { if (strcmp(name, stuList[j].name) == 0) break; } if (j < k) { stuList[j].scores[time - 1] = score; } else { strcpy(stuList[k].name, name); stuList[k].scores[time - 1] = score; k++; } } in.close(); return stuList; } int main() { int stuNum, hwNum; Student* stuList = Input("score.txt", stuNum, hwNum); for (int i = 0; i < stuNum; i++) { cout << stuList[i].name << "\t"; for (int j = 0; j < hwNum; j++) cout << stuList[i].scores[j] << "\t"; cout << endl; } return 0; }使之能运行

这段代码看起来是读取一个文件 "score.txt"，然后将文件中的数据存储到一个 Student 结构体数组中，并输出每个学生的姓名和成绩。但是，代码中有些问题，例如在结构体 Student 中没有定义析构函数，导致内存泄漏；并且没有进行输入文件是否存在的判断等等。

以下是修改后的代码：

#include <fstream>
#include <iostream>
#include <cstring>
using namespace std;

struct Student {
    char name[100];
    int* scores;
    double avg;
    ~Student() { delete[] scores; } // 添加析构函数
};

Student* Input(char* file, int& stuNum, int& hwNum) {
    ifstream in(file, ios::in);
    if (!in) { // 判断文件是否打开成功
        cerr << "Error: Cannot open file!" << endl;
        exit(1);
    }
    int itemNum;
    in >> stuNum >> hwNum >> itemNum;
    // 定义和初始化学生列表
    Student* stuList = new Student[stuNum];
    for (int i = 0; i < stuNum; i++) {
        stuList[i].scores = new int[hwNum];
        for (int j = 0; j < hwNum; j++)
            stuList[i].scores[j] = 0;
    }
    // 读入数据
    int k = 0;
    for (int i = 0; i < itemNum; i++) {
        char name[100];
        int time, score;
        in >> name >> time >> score;
        int j;
        for (j = 0; j < k; j++) {
            if (strcmp(name, stuList[j].name) == 0)
                break;
        }
        if (j < k) {
            stuList[j].scores[time - 1] = score;
        }
        else {
            strcpy(stuList[k].name, name);
            stuList[k].scores[time - 1] = score;
            k++;
        }
    }
    in.close();
    return stuList;
}

int main() {
    int stuNum, hwNum;
    Student* stuList = Input("score.txt", stuNum, hwNum);
    for (int i = 0; i < stuNum; i++) {
        cout << stuList[i].name << "\t";
        for (int j = 0; j < hwNum; j++)
            cout << stuList[i].scores[j] << "\t";
        cout << endl;
    }
    delete[] stuList; // 释放内存
    return 0;
}

修改后的代码中，添加了析构函数来避免内存泄漏，同时在文件打开失败时进行了错误处理。最后在 main 函数中添加了释放内存的操作，以避免内存泄漏。