Answer to Question #185167 in C++ for RAHUL SINGH

Question

Let we have to prepare the final result of each student for a particular subject. The final 

marks are sum of marks obtained by the student in T1, T2, T3, P1, P2, and attendance in theory class. Let 

there are following classes: Grade ‘A’ for> 80% marks, ‘B’ for 70 to 80%, ‘C’ for 60 to 70%, D for 50 to 60%, F for <50%.Base on above information, do the following:

(i) Write a function which prints the name and grades of all students in the ascending order of the 

grades. In case of same grade, print all respective names in alphabetical order.

(ii) Write a function which prints the name and grades of all students in the alphabetical order of 

the name of the students.

(iii) Write a function to search the grade of a student based on the first name of the student. In 

case of multiple entries with same name, print all the names with roll number and respective 

grades.

Answer 1

#include<iostream>
#include<bits/stdc++.h>
using namespace std;
map<string, vector<pair<long int, char>>>m;


class student{
	
	public:
		string name;
		int marks;
		int t1, t2, t3, p1, p2;
		char grade;
		long int rollno;
		
		void getGrade(int m)
		{
			if(m>80)
			{
				grade = 'A';
			}
			else if(m>70 && m<=80)
			{
				grade = 'B';
			}
			else if(m>60 && m<=70)
			{
				grade = 'C';
			}
			else if(m>50 && m<=60)
			{
				grade = 'D';
			}
			else{
				grade ='E';
			}
			
		}
		
		void input()
		{
			cout<<"Enter name of student : "<<endl;
			cin>>name;
			cout<<"Enter Roll no : "<<endl;
			cin>>rollno;
			cout<<"Enter marks in T1 : "<<endl;
			cin>>t1;
			cout<<"Enter marks in T2 : "<<endl;
			cin>>t2;
			cout<<"Enter marks in T3 : "<<endl;
			cin>>t3;
			cout<<"Enter marks in P1 : "<<endl;
			cin>>p1;
			cout<<"Enter marks in P2 : "<<endl;
			cin>>p2;
			int sum = (t1+t2+t3+p1+p2)/5;
			marks = sum;
			getGrade(marks);
			m[name].push_back(make_pair(rollno, grade));
		}
		
		void display()
		{
			cout<<"Name of student : "<<name<<endl;
			cout<<"Roll No : "<<rollno<<endl;
			cout<<"Marks obtained : "<<marks<<endl;
			cout<<"Grade : "<<grade<<endl;
		}
		
		
};


bool compareGrade(student a, student b)
{
	if(a.grade == b.grade)
	{
		return a.name < b.name;
	}
	return a.grade < b.grade;
}


bool compareName(student a, student b)
{
	return a.name < b.name;
}


void searchGrade(string nm)
		{
			bool ans = false;
			for(auto it = m.begin(); it!= m.end(); it++)
			{
				if(it->first == nm)
				{
					ans = true;
					for(int i=0; i < (it->second).size(); i++)
					{
						cout<<"Name of Student : "<<nm<<endl;
						cout<<"Roll No : "<<(it->second)[i].first<<endl;
						cout<<"Grade : "<<(it->second)[i].second<<endl;
						cout<<endl;
					}
				}
			}
			
			if(ans == false)
			{
				cout<<"This name is not found"<<endl;
			}
		}
		
		
int main()
{
	cout<<"Enter no. of students : "<<endl;
	int n;
	cin>>n;
	student s[n];
	
	for(int i=0; i<n; i++)
	{
		s[i].input();
		cout<<endl;
	}
	
	sort(s, s+n, compareGrade);
	cout<<endl<<endl;
	cout<<"Displaying student details in acsending order by Grade"<<endl;
	cout<<"-------------------------------------------------------------"<<endl;
	for(int i=0; i<n; i++)
	{
		s[i].display();
		cout<<endl;
	}
	sort(s, s+n, compareName);
	cout<<endl<<endl;
	cout<<"Displaying student details in acsending order by Name"<<endl;
	cout<<"-------------------------------------------------------------"<<endl;
	for(int i=0; i<n; i++)
	{
		s[i].display();
		cout<<endl;
	}	


	cout<<endl<<endl;
	cout<<"Enter the name you want to see grade : "<<endl;
	string nm;
	cin>>nm;
	cout<<"Details of asked name : "<<endl;
	cout<<"--------------------------"<<endl;
	searchGrade(nm);
	
	cout<<endl<<endl;
	cout<<"Displaying Student info"<<endl;
	cout<<"----------------------------"<<endl;
	for(int i=0; i<n; i++)
	{
		s[i].display();
		cout<<endl;
	}
}