banking management code returning junk values (using uml techniques) - class

Question

my project code on banking doesnt work properly. when i enter the branch and department info as i run (void department) in main .
and i display(void display) them junk values are returned,i think the values are not going in the linked list.
code made in code blocks
part of the code below:
#include<iostream>
#include<conio.h>
#include<cstdio>
#include<string.h>
#include<cstdlib>
#include<malloc.h>
using namespace std;
int code=1100;
int acc=9900;
int loan_no=3300;
int emp=10;
void createmenu();
void depositormenu();
void employee();
void loanmenu();
void operationmenu();
class branch
{
char bname[20];
int bcode;
branch *link;
public:
branch()
{
bcode=code++;
}
void input()
{
fflush(stdin);
cout<<"\nEnter Branch Name: ";
gets(bname);
}
void output()
{
cout<<"\nBranch Name: "<<bname;
cout<<"\tBranch Code: "<<bcode;
}
};
class department
{
char dname[30];
int dcode;
public:
branch *b;
department *link;
department()
{
b=new branch;
}
void input()
{
b->input();
fflush(stdin);
cout<<"Enter Department Code: ";
cin>>dcode;
fflush(stdin);
cout<<"Enter Department Name: ";
gets(dname);
}
void output()
{
b->output();
fflush(stdout);
cout<<"\nDepartment Name: "<<dname;
cout<<"\tDepartment Code: "<<dcode;
}
};
void departments(department **);
void display(department **);
department *start,*p=NULL;
void departments(department **start)
{
department *temp,*r,*temp2;
temp2=*start;
system("cls");
cout<<"\nEnter data for Departments->";
department d;
if(*start==NULL)
{
temp=(department*)malloc(sizeof(department));
d.input();
temp=&d;
temp->link=NULL;
*start=temp;
}
else
{
temp=*start;
while(temp->link!=NULL)
{
temp=temp->link;
}
r=(department*)malloc(sizeof(department));
r->input();
r->link=NULL;
temp->link=r;
}
}
void display(department **start)
{
department *temp;
temp=*start;
fflush(stdout);
if(temp==NULL)
{
cout<<"\nList not created!";
cout<<"\tPress any key to return";
getch();
}
else
{
while(temp)
{
temp->output();
temp=temp->link;
getch();
}
}
}
pls help.
thanks in advance

Answer 1

Since I can't see your input values and expected output values, I can't say for sure. However, since you've opted to using pointers for everything, the one thing I see is with this block of code in the departments function:
department d;
if(*start==NULL)
{
temp=(department*)malloc(sizeof(department));
d.input();
temp=&d; // you are assigning the address of a local variable to temp,
// and then assigning it to the argument pointer.
temp->link=NULL;
*start=temp;
}
If you assign the address of a local variable to an argument pointer and then reference it from outside the function, you will have lost that data.
My suggestion would be to assign the contents of the department to the start object, rather than use the local pointer address.
That is likely why you're seeing garbage data.
I'm surprised the compiler didn't say anything about that.