Question

这是一项大学任务，所以我更喜欢伪代码，或者只是对过程的基本概念;但是，任何帮助将不胜感激。

问题：

我有两个并行数组：array courseNames 和array maximumEnrollment 。我必须使用教师提供的函数，按字母顺序将新元素插入到数组 courseNames 中：

// Assume the elements of the array are already in order
// Find the position where value could be added to keep
//    everything in order, and insert it there.
// Return the position where it was inserted
//  - Assumes that we have a separate integer (size) indicating how
//     many elements are in the array
//  - and that the "true" size of the array is at least one larger 
//      than the current value of that counter

template <typename T>
int addInOrder (T* array, int& size, T value)
{
  // Make room for the insertion
  int toBeMoved = size - 1;
  while (toBeMoved >= 0 && value < array[toBeMoved]) {
    array[toBeMoved+1] = array[toBeMoved];
    --toBeMoved;
  }
  // Insert the new value
  array[toBeMoved+1] = value;
  ++size;
  return toBeMoved+1;
}

由于数组 courseNames 是空的，所以当我第一次使用该函数时，我不必担心数组是否正常。所有输入都来自由行分隔的文件，每行包含类的名称（ei.CS150）和允许的最大注册（ei.50）。第一个数组包含课程的名称，而第二个数组包含最大注册数。

我从文件中读取输入的函数的代码如下所示：

/*
 * Read the course names and max enrollments. Keep the courses
 * in alphabetic order by course name.
 */
void readCourses (istream& courseFile, int numCourses,
          string* courseNames, int* maxEnrollments)
{
  //!! Insert your code here
    for(int i =0; i < numCourses; ++i){
        string course;
        courseFile >> course;
        int pos = addInOrder(courseNames, numCourses, course);
        courseFile >> maxEnrollments[pos];
    }
}

我使用 courseNames 元素的位置作为索引来存储给定课程的最大注册人数。当一个新值插入 courseNames 并且我得到添加它的位置时，会出现问题。如果我使用该位置，索引的旧值将被覆盖，一切都将不合适。

我的问题是，我该如何防止这种情况发生？如何找出替换的值以保持数组的顺序并使并行数组 maximumEnrollment *与每个课程的 courseNames 的索引相匹配？

提前感谢您提供的任何帮助！

更新

我还提供了这个功能：

// Add value into array[index], shifting all elements already in positions
//    index..size-1 up one, to make room.
//  - Assumes that we have a separate integer (size) indicating how
//     many elements are in the array
//  - and that the "true" size of the array is at least one larger 
//      than the current value of that counter

template <typename T>
void addElement (T* array, int& size, int index, T value)
{
  // Make room for the insertion
  int toBeMoved = size - 1;
  while (toBeMoved >= index) {
    array[toBeMoved+1] = array[toBeMoved];
    --toBeMoved;
  }
  // Insert the new value
  array[index] = value;
  ++size;
}

所以我将代码更改为：

/*
 * Read the course names and max enrollments. Keep the courses
 * in alphabetic order by course name.
 */
void readCourses (istream& courseFile, int numCourses,
          string* courseNames, int* maxEnrollments)
{
  //!! Insert your code here
    int size = 1;
    for(int i =0; i < numCourses; i++){
        string course;
        int maxEnroll;
        courseFile >> course;
        courseFile >> maxEnroll;

        int pos = addInOrder(courseNames, size, course);
        addElement(maxEnrollments, size, pos, maxEnroll);

    }
}

按顺序添加新元素时保持并行数组更新

0 个答案: