谁能告诉我为什么当我尝试在菜单驱动的数组操作程序中调用 Insert 或 Delete 函数时我的程序崩溃？

Question

我正在尝试编写一个菜单驱动程序来执行创建、显示、插入和删除数组元素等操作。创建和显示函数工作得很好，但每当我尝试调用插入或删除函数时，程序就会崩溃，消息显示为进程已返回。我在下面分享了我的代码。我意识到创建功能并不理想，但我只是被告知要这样做。如果相关的话，我正在使用 Code::Blocks 20.03。

#include <stdio.h>
#define MAX 50
void create(int[],int);
void display(int[],int);
void insert(int[],int*,int,int);
void deletes(int[],int*,int);

int main()
    {
        int ch,n,a[MAX],ele,pos;
        while(1)
        {
            printf("\nChoose an operation\n");
            printf("1. Create\n2. Display\n3. Insert\n4. Delete\n5. Exit\n\n");
            scanf("%d",&ch);

            switch(ch)
            {
                case 1: printf("Enter the no. of elements\n");
                scanf("%d",&n);
                create(a, n);
                break;

                case 2: display(a, n);
                break;

                case 3: printf("Enter the position at which you want to insert the element\n");
                scanf("%d",&pos);
                printf("Enter the element to be inserted\n");
                scanf("%d",&ele);
                insert(a, &n, pos, ele);
                break;

                case 4: printf("Enter the position of the element to be deleted\n");
                scanf("%d",&pos);
                deletes(a,&n,pos);
                break;

                case 5: exit(0);

                default: printf("Invalid Input");
                break;
            }
        }
    }

    void create(int a[], int n)
    {
        int temp;
        printf("Please enter the elements\n");
        for(int i=0; i<n ; i++)
        {
            scanf("%d",&temp);
            a[i] = temp;
        }
    }

    void display(int a[], int n)
    {
        printf("The array is \n");
        for(int i=0;i<n;i++)
           {
               printf("%d\t",a[i]);
           }
            printf("\n");
    }

    void insert(int a[], int*n, int pos, int ele)
    {
        if(n==MAX)
        {
            printf("Array Overflow. Cannot Insert element\n");
        }
        else if(pos>=0 && pos<=n)
        {
            for(int i=n-1; i>=pos; i--)
            {
                a[i+1] = a[i];
            }
            a[pos] = ele;
            n++;
            printf("Element inserted successfully\n");
        }
        else
        {
            printf("Enter a valid position\n");
        }
    }

    void deletes(int *a,int*n, int pos)
    {
        if(pos<=n)
        {
            for(int i = pos-1; i<n;i++)
            {
                a[i] = a[i+1];
            }
            n--;
            printf("The element has been deleted\n");
        }
        else
            printf("Invalid position");
    }

感谢您的帮助！

Answer 1

在您的 insert 和 deletes 函数中，您没有取消引用作为参数给出的指针 (n)。您需要将 * 运算符添加到此变量以获取或设置 n 计数器的实际值。

对于insert函数，更正后的代码为：

void insert(int a[], int*n, int pos, int ele) // NOTE: "n" is a POINTER!
{
    if(*n==MAX) // Dereference n here
    {
        printf("Array Overflow. Cannot Insert element\n");
    }
    else if(pos>=0 && pos<=*n) // ... and here
    {
        for(int i=*n-1; i>=pos; i--) // ... and here
        {
            a[i+1] = a[i];
        }
        a[pos] = ele;
        (*n)++; // Note the brackets here - otherwise we increment the pointer!
        printf("Element inserted successfully\n");
    }
    else
    {
        printf("Enter a valid position\n");
    }
}

deletes 函数所需的更改非常相似。

Answer 2

发现了问题，n 是一个 simpel int 而不是数组，没有必要将它作为地址发送，所以我在 switch case 中做了什么：

case 3: printf("Enter the position at which you want to insert the element\n");
            scanf("%d", &pos);
            printf("Enter the element to be inserted\n");
            scanf("%d", &ele);
            insert(a, n, pos, ele);
            break;

        case 4: printf("Enter the position of the element to be deleted\n");
            scanf("%d", &pos);
            deletes(a, n, pos);
            break;

函数现在看起来像这样：

void insert(int a[], int n, int pos, int ele)

void deletes(int* a, int n, int pos)

谁能告诉我为什么当我尝试在菜单驱动的数组操作程序中调用 Insert 或 Delete 函数时我的程序崩溃？

Can anyone tell me why my program crashes when I try to call the Insert or Delete function in a menu driven array manipulation program?

c

arrays

insertion