using delete and free

i am unable to use "delete" and "free" on dev shed c++. i wonder whether its related to some header file. please help.

Can you post the simplest example which demonstrates the problem, and the exact error message you are getting?

Code:

/*c program to represent a queue as a singly linked list*/

#include<stdio.h>
#include<conio.h>
#include<stdlib.h>

struct node
{
     int data;
     struct node *link;
};

typedef struct node node;

void buildQueue(node *,int );
void display(node *);
void deleteQueue(node *);

int main()
{
     node *start;
     start=NULL;
     buildQueue(start,10);
     buildQueue(start,20);
     buildQueue(start,30);
     buildQueue(start,40);
     
     display(start);
 
     deleteQueue(start);
     deleteQueue(start);

     display(start);

     getch();
     return 0;
}

void buildQueue(node *root,int data)
{
      node *newnode;
      newnode=(node *)malloc(sizeof(node));
      newnode->data=data;
      newnode->link=NULL;
      if(root==NULL)
      {
            root=newnode;
      }
      else
      {
            newnode->link=root;
            root=newnode;
      }
}

void display(node *root)
{
     while(root!=NULL)
     {
           printf("%d",root->data);
           root=root->link;
     }
}

void deleteQueue(node *root)
{
      node *temp,*prev;
      temp=root;
      while(temp->link!=NULL)
      {
            temp=temp->link;
            prev=temp;
      }
      prev->link=NULL;
      delete temp;
}

i get 2 error messages in line number 75:"delete"undeclared and syntax error before"temp"

Eh, delete, as used in this context, is a C++ keyword, not C.

Code:

void deleteQueue(node *root)
{
      node *temp,*prev;
      temp=root;
      while(temp->link!=NULL)
      {
            temp=temp->link;
            prev=temp;
      }
      prev->link=NULL;
      delete temp;                  <--- free(temp);
}