Students sorting

/*
	Roll No: 101403051
	Name: Ayush Gupta
	Group: COE3
	Question: 1
 */

#include<bits/stdc++.h>
using namespace std;

class Student{
	private:
		long regNo;
		string name,branch;
		float cgpa;
	public:
		//Constructors: Default and parameterized
		Student() {}
		Student(long,const string,const string,float);

		//getter function for help in sorting
		long int getRegNo();

		//Pretty print student details
		void printStudentDetails();
};

Student::Student(long regNo,const string name,const string branch,float cgpa){
	this->regNo = regNo;
	this->name = name;
	this->branch = branch;
	this->cgpa = cgpa;
}

long int Student::getRegNo(){
	return regNo;
}

void Student::printStudentDetails(){
	cout<<"\n\nName: "<<name<<"\nRegNo: "<<regNo<<"\nBranch: "<<branch<<"\nCGPA: "<<cgpa<<"\n\n";
}

//Non class functions for sorting and searching

void swap(Student& a,Student& b){
	Student temp = a;
	a=b;
	b=temp;
}

Student linearSearch(long regNo,vector<Student>& students){
	for(int i=0;i<students.size();i++){
		if(regNo == students[i].getRegNo()){
			return students[i];
		}
	}
	throw "Student not found!";
}

//Ascending sort using bubble sort
void bubbleSort(vector<Student>& students){
    for(int i = students.size()-1;i>0;i--){
        bool flag = true;
        for(int j=i;j>0;j--){
            if(students[j].getRegNo()<students[j-1].getRegNo()){
				swap(students[j],students[j-1]);
                flag = false;									//One swap detected, array may not be sorted.
	    	}
        }
        if(flag) return;                    					//No swaps detected, array is sorted
    }
}

//Binary search on ascending sorted array
Student binarySearchRecursive(vector<Student>& students,long regNo,int leftIndex,int rightIndex){
	if(rightIndex<leftIndex) throw "Student not found!";					//Element not found
	int midIndex = (leftIndex+rightIndex)/2;
	if(students[midIndex].getRegNo()<regNo) return binarySearchRecursive(students,regNo,leftIndex,midIndex-1);
	else if(students[midIndex].getRegNo()>regNo) return binarySearchRecursive(students,regNo,midIndex+1,rightIndex);
	else return students[midIndex];
}

//Descending sort using insertion sort
void insertionSort(vector<Student>& students){
	for(int i=1;i<students.size();i++)
		for(int j=i;j>0 && students[j].getRegNo()>students[j-1].getRegNo() ;j--)
			swap(students[j],students[j-1]);
}


//Print student vector
void printAllStudents(vector<Student>& students){
	for(int i=0;i<students.size();i++){
		students[i].printStudentDetails();
	}
}

int main(){
	int n,x;
	cout<<"Enter no of students: ";
	cin>>n;
	vector<Student> s(n);
	cout<<"Enter details of students in format: \n Regno Firstname lastname branch cgpa\n";
	for(int i=0;i<n;i++){
		long regno;
		string fname,lname,branch;
		float cgpa;
		cin>>regno>>fname>>lname>>branch>>cgpa;
		s[i] = Student(regno,fname+" "+lname,branch,cgpa);
	}
	bool sorted = false;		//Keeps track whether array is sorted in right order for binary search
	do{
		long regNo;
		cout<<"\n\nSelect one of the following\n";
		cout<<"1. Search linearly for regno. \n";
		cout<<"2. Bubble Sort by Reg nos.(ascending order)\n";
		cout<<"3. Binary search for Reg no. \n";
		cout<<"4. Insertion sort by reg nos. (descending order)\n";
		cout<<"5. Print the students list\n";
		cout<<"Press any other button to exit\n\n";
		cout<<"Enter your choice: ";
		cin>>x;
		switch(x){
			case 0: break;
			case 1:
				cout<<"\nEnter the reg no. to be searched: ";
				cin>>regNo;
				try{
					Student student = linearSearch(regNo,s);
					student.printStudentDetails();
				} catch(const char* err){
					cout<<err<<endl;
				}
				break;
			case 2:
				bubbleSort(s);
				sorted = true;
				cout<<"\nStudents list is sorted in ascending order!\n";
				break;
			case 3:
				if(!sorted)
					bubbleSort(s);
				cout<<"Enter regNo to be searched: ";
				cin>>regNo;
				try{
					Student student = binarySearchRecursive(s,regNo,0,s.size());
					student.printStudentDetails();
				} catch(const char* err){
					cout<<err<<endl;
				}
				break;
			case 4:
				insertionSort(s);
				sorted = false;
				break;
			case 5:
				printAllStudents(s);
				break;
			default:
				return 0;
		}
	}while(x!=0);
	return 0;
}