Student record management system using linked list

Difficulty Level : Easy
Last Updated : 01 Dec, 2021

Prerequisites: Linked list

Problem: Create a student Record Management system that can perform the following operations:

Insert Student record
Delete student record
Show student record
Search student record

The student record should contain the following items

Name of Student
Roll Number of Student
Course in which Student is Enrolled
Total Marks of Student

Approach: With the basic knowledge of operations on Linked Lists like insertion, deletion of elements in the Linked list, the student record management system can be created. Below are the functionalities explained that are to be implemented:

Check Record: It is a utility function of creating a record it checks before insertion that the Record Already Exist or not. It uses the concept of checking for a Node with given Data in a linked list.
Create Record: It is as simple as creating a new node in the Empty Linked list or inserting a new node in a non-Empty linked list.
Search Record: Search a Record is similar to searching for a key in the linked list. Here in the student record key is the roll number as roll number is unique for every student.
Delete Record: Delete Record is similar to deleting a key from a linked list. Here the key is the roll number. Delete record is an integer returning function it returns -1 if no such record with a given roll number is found otherwise it deletes the node with the given key and returns 0.
Show Record: It shows the record is similar to printing all the elements of the Linked list.

Exception Handling

Although the implementation of exception handling is quite simple few things must be taken into consideration before designing such a system:

Roll Number must be used as a key to distinguish between two different records so while inserting record check whether this record already exists in our database or not if it already exists then immediately report to the user that record already exists and insert that record in the database.
The record should be inserted in sorted order for this to make the roll number a key and use the inserting node in the sorted linked list.

Below is the implementation of the above approach:

C++

// C++ program for the above approach
#include <bits/stdc++.h>
using namespace std;
 
// Node Class
class Node {
public:
    int roll;
    string Name;
    string Dept;
    int Marks;
    Node* next;
};
 
// Stores the head of the Linked List
Node* head = new Node();
 
// Check Function to check that if
// Record Already Exist or Not
bool check(int x)
{
    // Base Case
    if (head == NULL)
        return false;
 
    Node* t = new Node;
    t = head;
 
    // Traverse the Linked List
    while (t != NULL) {
        if (t->roll == x)
            return true;
        t = t->next;
    }
 
    return false;
}
 
// Function to insert the record
void Insert_Record(int roll, string Name,
                   string Dept, int Marks)
{
    // if Record Already Exist
    if (check(roll)) {
        cout << "Student with this "
             << "record Already Exists\n";
        return;
    }
 
    // Create new Node to Insert Record
    Node* t = new Node();
    t->roll = roll;
    t->Name = Name;
    t->Dept = Dept;
    t->Marks = Marks;
    t->next = NULL;
 
    // Insert at Begin
    if (head == NULL
        || (head->roll >= t->roll)) {
        t->next = head;
        head = t;
    }
 
    // Insert at middle or End
    else {
        Node* c = head;
        while (c->next != NULL
               && c->next->roll < t->roll) {
            c = c->next;
        }
        t->next = c->next;
        c->next = t;
    }
 
    cout << "Record Inserted "
         << "Successfully\n";
}
 
// Function to search record for any
// students Record with roll number
void Search_Record(int roll)
{
    // if head is NULL
    if (!head) {
        cout << "No such Record "
             << "Available\n";
        return;
    }
 
    // Otherwise
    else {
        Node* p = head;
        while (p) {
            if (p->roll == roll) {
                cout << "Roll Number\t"
                     << p->roll << endl;
                cout << "Name\t\t"
                     << p->Name << endl;
                cout << "Department\t"
                     << p->Dept << endl;
                cout << "Marks\t\t"
                     << p->Marks << endl;
                return;
            }
            p = p->next;
        }
 
        if (p == NULL)
            cout << "No such Record "
                 << "Available\n";
    }
}
 
// Function to delete record students
// record with given roll number
// if it exist
int Delete_Record(int roll)
{
    Node* t = head;
    Node* p = NULL;
 
    // Deletion at Begin
    if (t != NULL
        && t->roll == roll) {
        head = t->next;
        delete t;
 
        cout << "Record Deleted "
             << "Successfully\n";
        return 0;
    }
 
    // Deletion Other than Begin
    while (t != NULL && t->roll != roll) {
        p = t;
        t = t->next;
    }
    if (t == NULL) {
        cout << "Record does not Exist\n";
        return -1;
        p->next = t->next;
 
        delete t;
        cout << "Record Deleted "
             << "Successfully\n";
 
        return 0;
    }
}
 
// Function to display the Student's
// Record
void Show_Record()
{
    Node* p = head;
    if (p == NULL) {
        cout << "No Record "
             << "Available\n";
    }
    else {
        cout << "Index\tName\tCourse"
             << "\tMarks\n";
 
        // Until p is not NULL
        while (p != NULL) {
            cout << p->roll << "    \t"
                 << p->Name << "\t"
                 << p->Dept << "\t"
                 << p->Marks << endl;
            p = p->next;
        }
    }
}
 
// Driver code
int main()
{
    head = NULL;
    string Name, Course;
    int Roll, Marks;
 
    // Menu-driven program
    while (true) {
        cout << "\n\t\tWelcome to Student Record "
                "Management System\n\n\tPress\n\t1 to "
                "create a new Record\n\t2 to delete a "
                "student record\n\t3 to Search a Student "
                "Record\n\t4 to view all students "
                "record\n\t5 to Exit\n";
        cout << "\nEnter your Choice\n";
        int Choice;
 
        // Enter Choice
        cin >> Choice;
        if (Choice == 1) {
            cout << "Enter Name of Student\n";
            cin >> Name;
            cout << "Enter Roll Number of Student\n";
            cin >> Roll;
            cout << "Enter Course of Student \n";
            cin >> Course;
            cout << "Enter Total Marks of Student\n";
            cin >> Marks;
            Insert_Record(Roll, Name, Course, Marks);
        }
        else if (Choice == 2) {
            cout << "Enter Roll Number of Student whose "
                    "record is to be deleted\n";
            cin >> Roll;
            Delete_Record(Roll);
        }
        else if (Choice == 3) {
            cout << "Enter Roll Number of Student whose "
                    "record you want to Search\n";
            cin >> Roll;
            Search_Record(Roll);
        }
        else if (Choice == 4) {
            Show_Record();
        }
        else if (Choice == 5) {
            exit(0);
        }
        else {
            cout << "Invalid Choice "
                 << "Try Again\n";
        }
    }
    return 0;
}