【发布时间】：2021-11-07 19:46:33
【问题描述】：
所以我有一个 C++ 实验室，需要我打印出一个数组，删除一些数字，然后插入一些数字。我设法删除了正确的数字，然后在末尾插入数字，但我需要将数组按升序排序，例如：1、2、3、4。我认为这将是容易的部分，但它给我带来的麻烦比我想象的要多。我尝试使用带有嵌套 if 循环的 for 循环，该循环适用于普通数组，但我想在混合中涉及指针让我很难过。当前代码运行并执行除排序之外的所有操作。任何提示或帮助表示赞赏。代码和输出发布在下面。 This is an image of the assignment description
#include <iostream>
using namespace std;
class Array //The array class
{
private:
//Data members capacity, size, arr (a pointer that points to the first element of the array in the heap)v and two functions to move integers in the array.
int capacity{};
int size{};
int* arr{};
void moveTowardFront(int index);
void moveTowardEnd(int index);
public:
Array(int capacity);//parameter
~Array();//destructor
//two member function declarations
void insert(int num);
void print() const;
void remove(int num);
};
//insert method
void Array::insert(int num)
{
{
//if size is 0, then move number taken from insert call into the first element of the array and increment size before returning
if (size == 0)
{
arr[0] = num;
size++;
return;
}
int index = 0;
while (&num < &arr[index] && index < size) //while the address of the number taken from insert function call is less than the address of the element [index] in the arr array
//and the index is less than the size of the array
{
index++; //then we increment the index
}
moveTowardEnd(index); //move value of element toward the end
//after the while loop we move the value of the number taken from main insert call into the arr element [index] after it has been incremented so we don't overwrite values
arr[index] = num;
size++;
//then we increment the size of the array because a new value has been inserted
}
}
// Delete member function
void Array::remove(int num)
{
int index = 0; //start index at 0
//while number from main is not equal to the array element of index and the index is smaller than the size, we increment the index
while (num != arr[index] && index < size)
{
index++;
}
//if index is equal to the size then output the number from main and say it isn't on the list so no removal
if (index == size)
{
cout << num << " is not in the list. ";
cout << "No removal." << endl;
return;
}
//move toward front function call on index value and post-increment. Then post-decrement size
moveTowardFront(index++);
size--;
}
//print method
void Array::print() const
{
//rearrange the digits in ascending order
for (int i = 0; i < size; i++)
{
//print out values based on value of size taken from insert method
cout << *(arr+i) << " "; //arr points to first element in heap and then moves over by i to the next element for each iteration
}
}
// Helper function to move the elements of array towards end
void Array::moveTowardEnd(int index)
{
int* temp = &arr[index];
int* temp2 = &arr[size-1];
arr[index] = *temp2;
arr[size] = *temp;
return;
}
// Helper function to move the elements of array towards front
void Array::moveTowardFront(int index)
{
int* temp = &arr[index];
int* temp2 = &arr[size-1];
arr[index] = *temp2;
arr[size] = *temp;
return;
}
//Destructor to clean up by deleting the space allocated
Array::~Array()
{
delete[]arr;
}
//Parameter constructor to allocate space
Array::Array(int cap)
:capacity(cap)
{
//move space allocated by array with capacity being taken from main into the arr pointer so pointer can point to first element in heap
arr = { new int[capacity] {} };//allocating memory with the new operator
size = 0;//initialize size to 0
}
int main()
{
// Declaration of any array of capacity 20
Array array(20);
// Inserting some elements and printing array
array.insert(15);
array.insert(13);
array.insert(10);
array.insert(14);
array.insert(11);
array.insert(17);
array.insert(14);
cout << "Printing array after insertions: " << endl;
array.print();
cout << endl;
// Removing two elements and printing array
array.remove(13);
array.remove(11);
cout << "Printing array after removals: " << endl;
array.print();
cout << endl;
// Inserting two more elements and printing array
array.insert(8);
array.insert(22);
cout << "Printing array after more insertion" << endl;
array.print();
cout << endl;
// Try to remove an element, which is not in the array
array.remove(31);
return 0;
}
【问题讨论】：
-
我会冒险出去，猜你不能调用std::sort？但这归结为两个问题之一 - 您必须对底层数组进行排序，这与所有这些代码没有任何关系，或者您必须处理其他问题，例如内存管理错误。