Question

在创建数组后的程序中，用户可以选择和删除数组中的一个元素。
之后，程序将显示不包含此元素的数组。

此作业的要求是使用指针。

using namespace std;

int main()
{
    int *x = NULL;
    int n;
    int cyfry;

    cout << "podaj dlugosc listy\n"; // array lenght
    cin >> n;

    x = new int[n];
    cout << "podaj cyfry do listy\n";
    for (int i = 0; i < n; i++) {
        cin >> cyfry;
        x[i] = cyfry;  // input values to array
    }

    for (int i = 0; i < n; i++) // values in array
        cout << x[i] << ",";
}

Answer 1

想象一下您要删除用户输入的数组元素中的一个的情况。这不是一个完美的解决方案，因为newArray仅少了1个元素，并且您需要删除所有元素。但这是因为您有了如何做的想法！您还没有尝试过一件事情（至少从您给我们看的东西上）。

将此汇总为您已经拥有的代码：

     newArray = new int[n-1];
        int toDelete;
        cin>>toDelete;
        int j=0;


       /*this deletes ALL elements that are, for example, "2" of the array of ints.
     If you want to delete only the first found, 
you can use a boolean (or a int found=0;), 
and in the if case, use this found*/

        for(int i=0;i<n;i++){
            if(toDelete!=x[i]){
            /*we use "j" because newArray has 1 less element than x. So we will be adding numbers
            in case the element is the one we want to delete, we do not add it, so j does not sum up. */
                newArray[j]=x[i];
                j++;
            }

        }

在您的代码中for循环中执行此操作，然后执行与代码有关的操作！希望这个例子能解决您的疑问！

编辑：在这种情况下（如问题几个月前的几个小时前所问），在这种情况下，您只想删除元素的第一次遇到：f.e：

[1,2,3,1,2,3,1,2,3]，要删除的元素为2，最后一个数组：[1,3,1,2,3,1,2,3]

#include <iostream>

using namespace std;

int main()
{
        int size=9;
        int* firstArray=new int[size];
        //just an example to add up the array. This is quite dirty, but as to see the easy example
        firstArray[0]=1;
        firstArray[1]=2;
        firstArray[2]=3;
        firstArray[3]=1;
        firstArray[4]=2;
        firstArray[5]=3;
        firstArray[6]=1;
        firstArray[7]=2;
        firstArray[8]=3;
        for (int i=0;i<size;i++)
            cout<<firstArray[i];
        cout<<endl;
        int* newArray = new int[size-1];
        int toDelete;
        cin>>toDelete;
        int j=0;
        bool counter=false; //this counter will tell us if we have deleted it once
        //[1,2,3,1,2,3,1,2,3]
        for(int i=0;i<size;i++){
            //if the element we want to delete, is not in the array
            if(toDelete!=firstArray[i]){
                newArray[j]=firstArray[i];
                j++;
            }
            //if we find the element to delete and we have not deleted it yet, we dont copy it
            else if (toDelete==firstArray[i] && counter==false) {
                counter=true;
            }
            //if we have already deleted it, nothing. 
             else if (toDelete==firstArray[i] && counter==true) {
                newArray[j]=firstArray[i];
                j++;

            }


        }
        for (int i=0;i<size-1;i++)
             cout<< newArray[i];
}

Answer 2

这里：

int main()

    int* wskaznik = NULL;
    int ile;
    int cyfry;

    cout << "podaj dlugosc listy\n";
    cin >> ile;

    wskaznik = new int[ile];
    cout << "podaj cyfry do listy\n";

    for (int i = 0; i < ile; i++) {
        cin >> cyfry;
        wskaznik[i] = cyfry;
    }

    for (int i = 0; i < ile; i++)
        cout << wskaznik[i] << ",";

    int* n_wskaznik = new int[ile - 1];

    int usun;
    / int j = 0;
    cin >> usun;

    int znajdz = 0; // potrzebny mechanizm wybierający tylko pierwszy element

    for (int i = 0; i < ile; i++) {
        if (usun != wskaznik[i]) // '==' pokarze wybrane,  '!+' usunie wybrane
        {

            n_wskaznik[j] = wskaznik[i];
            j++;
            cout << wskaznik[i] << ",";
        }
    }
    return 0;
}

C ++如何通过用户输入删除列表元素

2 个答案: