Trying to delete node from a particular position . But I can only delete when in only input position-CodePudding

after running the code ,the program ask the position from where you want to delete a node . I ran the code but it only work when I input postion 1 .For other position like 2,3,4 it does not work .

here i want to insert number at end of a node :

void Insert(int data)
{
    struct node* temp1;
    temp1=(struct node*)malloc(sizeof(struct node));
    temp1->data=data;
    temp1->next=NULL;

    if (head==NULL){
        temp1->next=head;
        head=temp1;
    }
    else{
        struct node* temp2;
        temp2=head;
        while(temp2->next!=NULL)
        {
            temp2=temp2->next;
        }

        temp2->next=temp1;
    }
}

Print function:

void Print()
{
    struct node*temp99;
    temp99=head;
    while(temp99!=NULL){
        printf(" %d",temp99->data);
        temp99=temp99->next;
    }
    printf("\n");
}

Delete function:

void Delete(int n)
{
    struct node* temp33;
    temp33=head;

    if (n==1)
    {
        head=temp33->next;
        free(temp33);
    }
    else{
        int i;
        for (i=0;i<n-2;i  )
        {
            temp33=temp33->next;
        }
        struct node* temp44;
        temp44=temp33->next;

        temp44->next=temp33->next;

        free(temp44);
    }
}

CodePudding user response：

Replace temp44->next=temp33->next; with temp33->next=temp44->next;.

And give better names to your variables.

CodePudding user response：

For starters indices shall start from 0. Secondly the function parameter shall have an unsigned integer type as for example size_t.

When n is not equal to 1 these manipulations with pointers

    struct node* temp44;
    temp44=temp33->next;

    temp44->next=temp33->next;

    free(temp44);

do not make a sense. For example data member next of the pointer temp33 is not changed.

And moreover this for loop

    for (i=0;i<n-2;i  )
    {
        temp33=temp33->next;
    }

can invoke undefined behavior because there is no check whether temp33 is not equal to NULL.

Even this code snippet

if (n==1)
{
    head=temp33->next;
    free(temp33);
}

can invoke undefined behavior when the list is empty that is when head is equal to NULL.

The function can be defined the following way

int Delete( size_t n ) 
{
    struct node **current = &head;

    while ( *current != NULL && n )
    {
        current = &( *current )->next;
        --n;
    }

    int success = *current != NULL;

    if ( success )
    {
        struct node *node_to_delete = *current;
        *current = ( *current )->next;
        free( node_to_delete );
    }

    return success;
}