Question

hey I have this program written in c++ and I have a problem with if statement {} brackets and I was wondering if someone can fix it.

//Name: Group1_QueueImplementation.cpp

//made by ibrahem alrefai

//programming project one part 4

//group members: Mohammad Bayat, Seungmin Baek,Ibrahem Alrefai

#include <iostream>

#include<stdlib.h>

using namespace std;

struct node { string data; struct node* next; };

struct node* front = NULL;

struct node* rear = NULL;

struct node* temp;

void Insert()

{

    string val;

    cout << "enter element to insert : ";

    cin >> val;

}

//problems start here

if (rear == NULL)

{

    rear = (struct node*)malloc(sizeof(struct node));

    rear->next = NULL;

    rear->data = val;

    front = rear;

}

else

{

    temp = (struct node*)malloc(sizeof(struct node));

    rear->next = temp;

    temp->data = val;

    temp->next = NULL;

    rear = temp;

}

    }

}

void Delete()

{

    temp = front;

    if (front == NULL)

    {

        cout << "Underflow" << endl;

        return;

    }

    else

    {

        if (temp->next != NULL)

        {

            temp = temp->next;

            cout << "deleting :" << front->data << endl;

            free(front);

            front = temp;

        }

        else {

            cout << "deleting : " << front->data << endl;

            free(front);

            front = NULL;

            rear = NULL;

        }

]

    }

}

void Display()

{

    temp = front;

    if ((front == NULL) && (rear == NULL))

    {

        cout << "Queue is empty" << endl;

        return;

    }

    cout << "Queue elements are: ";

    while (temp != NULL)

    {

        cout << temp->data << " ";

        temp = temp->next;

    }

    cout << endl;

}

void form_queue()

{

    int n;

    cout << "Enter number of elements : " << endl;

    cin >> n;

    int i = 0;

    while (i < n)

    {

        Insert();

        i++;

    }

}

void delete_all()

{

    while (front != NULL)

        Delete();

}

        }

        int main()

        {

            form_queue();

            Display();

            delete_all();

            Display();

            return 0;

        }

Answer 1

#include <iostream>

#include<stdlib.h>

using namespace std;

struct node { string data; struct node* next; };

struct node* front = NULL;

struct node* rear = NULL;

struct node* temp;

void Insert()

{

string val;

cout << "enter element to insert : ";

cin >> val;

//problems start here

if (rear == NULL)

{

rear = (struct node*)malloc(sizeof(struct node));

rear->next = NULL;

rear->data = val;

front = rear;

}

else

{

temp = (struct node*)malloc(sizeof(struct node));

rear->next = temp;

temp->data = val;

temp->next = NULL;

rear = temp;

}

  

}

void Delete()

{

temp = front;

if (front == NULL)

{

cout << "Underflow" << endl;

return;

}

else

{

if (temp->next != NULL)

{

temp = temp->next;

cout << "deleting :" << front->data << endl;

free(front);

front = temp;

}

else {

cout << "deleting : " << front->data << endl;

free(front);

front = NULL;

rear = NULL;

}

}

}

void Display()

{

temp = front;

if ((front == NULL) && (rear == NULL))

{

cout << "Queue is empty" << endl;

return;

}

cout << "Queue elements are: ";

while (temp != NULL)

{

cout << temp->data << " ";

temp = temp->next;

}

cout << endl;

}

void form_queue()

{

int n;

cout << "Enter number of elements : " << endl;

cin >> n;

int i = 0;

while (i < n)

{

Insert();

i++;

}

}

void delete_all()

{

while (front != NULL)

Delete();

}

int main()

{

form_queue();

Display();

delete_all();

Display();

return 0;

}