DataStructuresAndAlgorithms/Codes/Practical-F23.cpp

// WARNING: THIS CODE HAS NOT BEEN TESTED. 
// IT WILL TAKE 1-2 MONTHS TO PERFECT THE CODE. 
// IF YOU FACE ANY ERRORS, UNEXPECTED BEHAVIOUR OR HAVE ANY SUGGESTIONS, 
// LET US KNOW BY CREATING AN ISSUE ON OUR KSKA GIT REPOSITORY.

/*
Problem Statement: Department maintains a student information. The file contains roll number, name, division and address. Allow user to add, delete information of student. Display information of particular employee. If record of student does not exist an appropriate message is displayed. If it is, then the system displays the student details. Use sequential file to main the data.

Code from Data Structures and Algorithms (SPPU - Second Year - Computer Engineering - Content) repository on KSKA Git: https://git.kska.io/sppu-se-comp-content/DataStructuresAndAlgorithms/
*/

// BEGINNING OF CODE
#include<iostream>
#include<fstream>
using namespace std;

class student
{
	public:
	char name[10];
	int roll;
		void getdata()
		{
			cout<<"\n Enter the roll no and name:";
			cin>>roll>>name;
		}
	
		void putdata()
		{
			cout<<"\n The roll no and name:";
			cout<<roll<<"    "<<name;
		}
	
};

class file
{
	fstream fp;
	public:
		void create()
		{
			char ans;
			student s;
			fp.open("stu.dat",ios::out);
			do
			{
				s.getdata();
				fp.write((char *)&s,sizeof(s));
				cout<<"\n More?";
				cin>>ans;
			}while(ans=='Y'||ans=='y');
			fp.close();
		}
                void append()
		{
			char ans;
			student s;
			fp.open("stu.dat",ios::app);
			do
			{
				s.getdata();
				fp.write((char *)&s,sizeof(s));
				cout<<"\n More?";
				cin>>ans;
			}while(ans=='Y'||ans=='y');
			fp.close();
		}
		void display()
		{
			student s;
			fp.open("stu.dat",ios::in);
			while(!fp.eof())
			{
				fp.read((char *)&s,sizeof(s));
				if (!fp.eof()) 
					s.putdata();
			}
			fp.close();
		}
                void search()
		{
			student s; int flag=0;
                        cout <<"\n Enter roll to be searched:";
                        int r;  cin >> r;
			fp.open("stu.dat",ios::in);
			while(!fp.eof())
			{
				fp.read((char *)&s,sizeof(s));
				if (!fp.eof() && s.roll==r) 
                                {  flag=1;  s.putdata(); break;    }
			}
                        if (flag==0)  cout << "\n Not found";
			fp.close();
		}
		void update()
		{
			student s; int flag=0;
                        cout <<"\n Enter roll to be updated:";
                        int r;  cin >> r;
			fp.open("stu.dat",ios::in|ios::out);
			while(!fp.eof())
			{
				fp.read((char *)&s,sizeof(s));
				if (!fp.eof() && s.roll==r) 
                                {  
                                  flag=1;  
                                  cout <<"\n Enter new data\n";
                                  s.getdata();
                                  fp.seekp(-1*sizeof(s),ios::cur);
                                  fp.write((char *)&s,sizeof(s));  
                                  break;    
                                }
			}
			
                        if (flag==0)  cout << "\n Not found";
			fp.close();
		}
		void delete1()
		{
			student s; int flag=0;
			fstream fp1;
                        cout <<"\n Enter roll to be deleted:";
                        int r;  cin >> r;
			fp.open("stu.dat",ios::in);
			fp1.open("temp.dat",ios::out);
			while(fp.read((char *)&s,sizeof(s)))
			{
				
				if ( s.roll!=r)
                        {  
                        	flag=1;
				   	fp1.write((char *)&s,sizeof(s));
                        }
			}
                        if (flag==0)  cout << "\n Not found";
			fp.close();
			fp1.close();
			remove("stu.dat");
			rename("temp.dat","stu.dat");
		}
};


int main()
{
	file f; int choice;
        do{
           cout << "\n1 create \n 2 display \n 3 Search \n 4 Append";
           cout << " \n 6 delete \n 7 Update";
           cout << "\n Enter choice:";  cin >> choice;
           switch(choice)
           {
               case 1:f.create(); break;
               case 2:f.display(); break;
               case 3:f.search(); break;
               case 4:f.append(); break;
	       case 6:f.delete1();break;
	       case 7:f.update();break;
           }
       }while(choice< 8);
}
// END OF CODE
// EXPERIMENTAL CODE